Keywords

1 Introduction

Response to external or environmental stimuli is a characteristic feature of all living organisms, and humans are no exception. However, there are variations from individual to individual in their physiological responses to stimuli. These external stimuli include climate, food, and even the drugs and medicines that we consume. A specific environmental temperature may be comfortable for one person but be felt as cold and uncomfortable for another. This is one example of a wide range of individual variations that are considered in the treatment of diseases in the PM but not in the conventional medical approach.

Why does disease severity differ in different people exposed to the same pathogen or risk factor in similar conditions? What causes diverse therapeutic effects and side effects of drugs in patients suffering from the same disease? Why is susceptibility to disease different among individuals? And finally, why are the treatment responses so diverse?

These questions have led to establishing a new trend in medical sciences called personalized medicine. Nutrigenomics, pharmacogenomics, and metabolomics are examples of emerging scientific fields based on which prediction of susceptibility to diseases, reactions to food, and medicines are possible considering individuals’ genomic, metabolic, and biochemistry characteristics (Bates 2010; Jafari et al. 2014).

However, access to people’s genetic background (genotype) is neither cheap nor available for the public. Centuries ago, physicians in Persia and Greece noticed these differences in the personal characteristics of people from the same race or tribe. They assessed and understood the potential links between these psychological traits, body functions and physiology, susceptibility to various diseases and responses to treatment. Based on experiences and analysis of observations, these physicians found a pattern named hot and cold classification that could represent the body system variations. They called the basis of this classification “Mizaj” (also called “temperament,” “constitution,” and “nature” (Naseri et al. 2010)).

There is a particular emphasis on a holistic approach to health as the human is to be seen as an interrelated system in PM. The principles of health maintenance, prevention, and treatment in PM, are determined based on the Mizaj foundation which requires both a holistic and personalized view to the patient (Rafieian-kopaei et al. 2016; Zulkifle 2014). Mizaj identification in this school of medicine is so essential that without it, PM loses its basic concept and is degraded into merely a type of herbal medicine.

2 Methods

This study is a narrative review to determine the characteristics of the hot and cold theory of Mizaj based on PM literature. In the first step, all of the information related to keywords including “Mizaj identification,” “hot,” “cold,” “temperament,” “Mizaj,” “Persian Medicine,” “humoral medicine,” and “Unani medicine” were extracted from the most trusted PM textbooks, including Al-Qanun fi al-Tibb (The Canon of Medicine), Kamil al-Sinaa al Tibbiyah, Liber Al-Mansuri, Hedayat al Mota'allemin fi al-Tibb, and Kholasat al-Hikmah. The search for these keywords was performed in Cochrane, Web of Science, Science Direct, Scopus, PubMed, Google scholar, and SID from 2000 to 2020. We reviewed the extracted data, kept relevant information related to hot–cold theory and its identification, and then summarized the information within our group to write this chapter.

3 Case Presentation

Sheila (a real case with fictitious name to protect patient privacy; informed consent was obtained) was a 36-year-old woman who presented with a complaint of secondary infertility to Shahid Beheshti University’s traditional medicine clinic. She had been trying to conceive for 6 years. During that time, she had two miscarriages at 8 weeks diagnosed as blighted ovum. The patient had dyspepsia and felt heavy after eating heavy meals, such as pasta and pizza. She was experiencing gas and bloating while eating cold-natured foods such as yogurt, buttermilk, and cucumber. She had constipation (firm stool and bowel movements every 2–3 days). She had menstrual issues including long cycles (40–50-day cycles) and reduced flow (oligohypomenorrhea).

She was taking 500 mg Ibuprofen twice a day for dysmenorrhea. She also reported low libido. The patient complained of a feeling of coldness in the hypogastric and buttock regions. Moreover, she was suffering from poor sleep quality, occasional nightmares, and startling awake several times during night sleep. To compensate, she used to take a nap for 2–3 hours in the afternoon. Infertility caused a lot of stress and anxiety for her. Her hair color was brown but started to turn grey at the age of 35. She was an obese class I (BMI = 32 kg/m2) and her repeated attempts to lose weight had failed. She felt asthenia on low-calorie diets and salads (lettuce and cucumber), which made her discontinue the diet. The patient was on 25 µg Levothyroxine daily for borderline hypothyroidism.

On physical examination, vital signs were within normal limits. She had light-colored skin, a small frame, and a large, pale, and wet tongue. Her pulse was considered slow and weak according to the PM pulsology. Her extremities were cold, and she stated that others were surprised by her hands’ coldness when shaking hands with her. On vaginal examination, a considerable amount of non-infectious white discharge was seen, although she was not in the ovulation stage. The vagina and cervix were pale.

In para-clinical investigations, FSH and LH were 19.9 IU/L and 22 IU/L, respectively. TSH was 2.7 mIU/L. Other routine blood tests were normal. In hysterosalpingography, fallopian tubes were reported to be patent. Transvaginal ultrasound was normal. Her spouse had a normal spermogram. The diagnosis was “unexplained infertility” according to the fertility clinic report.

4 History

Persian Medicine is a traditional school of medicine with thousands of years of history. This school results from the many years of experience and efforts made by great scientists in a vast geographical region. Based on the available evidence, the origin of this school was ancient Persia and Greece (Tountas 2009; Zargaran 2014). This school is recognized as “Persian Medicine” in Iran, “Unani Medicine” in India, and “Humoral medicine” and “Mizaj Teb” in other parts of the world.

There is some evidence of medical science and practice in ancient Persia (Iran) before Christ (Zargaran et al. 2013; Shoja and Tubbs 2007). The concept of Mizaj as the basis of individual differences was rooted in philosophers and physicians of Persia and ancient Greece. Hippocrates (370–460 BC) pioneered the idea of humors and individual differences, and Galen (129–216 AC) completed this theory with physiological commentaries (DeLisi and Vaughn 2014; Strelau 1998). Subsequently, during the Sassanid Dynasty in Iran (226–652 AC), this school thrived more in the University of Jondishapour with scientists from many parts of the world (Zargaran 2014). In the third stage, Muslim scientists such as Ali-Ibn Rabn Tabari (838–870 AD), Rhazes (865–925 AD), Avicenna (980–1037 AD), Al-Akhawayni Bukhari (?–983 AD), and Ali-Ibn Abbas Majusi Ahvazi (949–982 AD) further developed this school. The books written by these scientists, such as Canon in Medicine, were translated into Latin and other languages in the twelfth century and became the leading medical references in European universities (Cruse 1999; Modanlou 2011). Following the emergence of conventional medicine, attention to PM declined gradually. However, in some countries like Iran, India, and Pakistan, it still has followers, so, it is taught in academic centers and practiced in health care settings (Rezaeizadeh et al. 2009; Zargaran 2019).

Since 1921, this school of medicine has continued to exist under Unani Medicine’s title as a university major in India, and Mahatma Gandhi founded the first Unani Medicine College in New Delhi. The main emphasis of India’s university centers in the recent decades has been educating practitioners to provide service for the Indian public. Recently, more attention has been paid to the research and development of scientific documentation in India’s academic centers (Lloyd 2009). Since 2007, the Iranian government has approved this school of medicine as a university Ph.D. program called Persian Medicine, with the main focus on research and development based on scientific evidence. Currently, there are 14 academic research centers and 22 departments of Persian medicine in Iran conducting research on the fundamental theories and clinical applications of this school of medical practice (Rezaeizadeh et al. 2009; Zargaran 2019).

5 Definition

“Mizaj” is sometimes translated as “temperament” in English, which is derived from the Latin word “temperamentum,” meaning “mixed”. Although originally this term was derived from the traditional concept of Mizaj in Persia and Greece, this word has a psychological connotation that deals with moral–mental characteristics, personality types, and individual differences in emotions and behaviors. Hence, the meaning interpreted from the word “temperament” in psychology cannot account for the vast concept of “Mizaj” in PM, which considers both physical–physiological and behavioral–mental characteristics (Cloninger 1994; Hoosen 2017). Therefore, we will use the word “Mizaj” in this chapter to convey the meaning more efficiently.

In practice, the concept of Mizaj is a classification based on between-person variations in physical, physiological, and psychological characteristics. Each person’s unique phenotypic characteristic, the physical, physiological, and behavioral characteristics originates from gene–environment interaction. Therefore, in some cases, especially in clinical applications, the phenotype can be used as a representative of the genotype in making decisions about individualized treatment strategies (Naseri et al. 2010).

5.1 Elements

Elements are part of the philosophical explanation of the Mizaj concept in PM, so, we will briefly explain it here. PM scholars believed that all living and non-living beings, including humans, consist of primary particles called elements (Arkan). Their definition of elements was that they could not be broken down into smaller particles. In other words, elements are the final stages of particle decomposition in the world of creation. According to the PM, these elementary particles are invisible and can be detected by the traces they leave behind or the phenomena they bring about (Avicenna 2005).

Persian scientists chose some names for elements based on natural objects that were familiar for people and based on their features. They include fire, air, water, and earth. The fire element has features similar to natural fire, but it is distinct from the actual fire. It releases heat, is in motion, is a source of energy, increases the space between components of a whole, and expands. The fire also dries up humidity. Regarding earth, they believed that there should be an element to cause firmness and solidity of a creature’s form, and since natural earth has these features, this element has been called earth. Since natural earth is colder than the fire in temperature and heavier in weight, it is motionless, dry, and compact. Names specified for the other two elements, air and water, are on the same basis. Like steam, the air element contains more heat than water and, like gas, can easily take the form of its container. The water element is fluid like natural water; it is formable and has features of coldness and wetness (Shirbeigi et al. 2017).

The body consists of four vital fluids called humors including black bile, yellow bile, blood, and phlegm. In each of these humors, one of the above elements is dominant. Air is the dominant element in blood, fire is the dominant element in yellow bile, water is the dominant element in phlegm, and earth is the dominant element in black bile (Aghili Shirazi 2006).

According to the PM, each one of these elements has specific characteristics, by which their presence can be identified. Four primary qualities of hotness, coldness, dryness, and wetness were proposed regarding features of the elements. From which hotness–coldness are considered dominant qualities and wetness–dryness are non-dominant qualities. The element of fire is light with hot and dry qualities; the element of air is relatively light with hot and wet qualities; the element of water is somewhat heavy with cold and wet qualities; and the element of earth is absolutely heavy with cold and dry qualities. In other words, the elements of fire and air are hot, and the elements of water and earth are cold (Shirbeigi et al. 2017). The hotness of elements implies far-spaced parts, expansion, lightness, and motion. In the human body, this quality is the primary energy source, power of living, and motion. In contrast, coldness in elements suggests dense parts, constancy, solidity, and tranquility. The role of this quality in the human body is regulating extra heat, compressing components, creating appropriate density in body tissues, and preserving the body from excessive excretion (Majusi Ahwazi 2008).

5.2 The Concept of Mizaj

The human body is composed of four elements and each element has its features of hotness, coldness, dryness, and wetness. Therefore, the combination of elements also has unique characteristics, according to the proportion of elements. The uniform quality resulting from the combination of elements in each being, including the human body, is called “Mizaj”. Usually, the elements are in relative balance; therefore, the Mizaj is temperate, but in some people, one or some elements are dominant, so, they present typical features of those elements (Mizaj types). For instance, a hot-tempered person (with the dominance of fire) is very hasty, moves quickly, becomes angry quickly, speaks fast, makes social contact easily, has a high metabolism, often feels hot, cannot stand the heat, does not wear heavy clothes even in cold seasons, and has more tendency to use cooling systems like fans and air conditioners in hot seasons than others. On the contrary, a cold-tempered individual with higher levels of earth or water element is patient, cool, slow-moving, rarely becomes angry, speaks slowly, is not very social, hardly speaks, has a low metabolism, feels less warm, cannot stand cold weather, and uses thick warm clothes, especially in cold seasons (Avicenna 2005).

Likewise, the difference in the proportion of elements and the four qualities, in other beings, foods, and medicinal substances can be generalized. For example, foods and medicine with a higher proportion of fire than other elements, are warm-natured, inducing hotness in the body and increased metabolism. In contrast, food and medicine that contain cold elements like earth are cold-natured and lead to coldness, decreasing body metabolism. It is pertinent to mention that Mizaj is a relative concept. When, for instance, we say a person has a cold Mizaj, it does not mean that they have no warmness in their bodies but rather indicates that the person has less warmness than someone with a hot Mizaj (Razes 2008).

6 Types of Mizaj

Each person’s body is composed of a unique proportion of elements. This means everyone has their individual Mizaj. Despite this broadness in types of Mizaj, to specify Mizaj more easily, PM scientists have divided Mizaj into nine groups and considered each group along a spectrum. For instance, cold Mizaj has a spectrum, ranging from extreme coldness to very mild coldness (Fig. 3.1). The signs and symptoms of each person’s Mizaj is on a spectrum of coldness–hotness and also wetness–dryness (Avicenna 2005).

Fig. 3.1
figure 1

Mizaj (Temperaments) types

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The horizontal axis displays Hot–Cold degrees, with the cold degree to the left. The vertical axis indicates Wet–Dry degrees with points lower than balanced being dry and higher points being wet. The PM nine main Mizaj types (healthy Mizaj types) include Temperate, Hot, Cold, Dry, Wet, Hot-Wet, Cold-Wet, Hot-Dry, and Cold-Dry. Temperament changes eventually lead to dysfunction of the body, at this stage, it is named dystemperament. If one of the four humors becomes more than normal, it is called Humoral dominance. For example, Hot–Dry dystemperament is sometimes called Yellow Bile dominance.

7 Identification of Mizaj

There are ten clinical characteristic criteria including physical, physiological, and psychological features which are used in practice to determine a person’s Mizaj type (Mojahedi et al. 2018) (Table 3.1).

Table 3.1 The ten criteria of Mizaj identification
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Touch: Shaking hands, everyone feels that another person’s hands are warmer or colder than theirs. The warmness of the skin to touch is a sign of hot Mizaj, while coldness is indicative of a cold Mizaj. Since ambient temperature alters skin temperature, the person should remain at room temperature for enough time to properly assess this index (Yousefifard et al. 2018).

Obesity and Thinness: Among individuals with the same diet and physical activity, and with normal clinical and laboratory evaluations, some are susceptible to obesity, and some are thin and have difficulty reaching their ideal weight. In individuals with a higher weight to height ratio, those with more muscle than fat gain a score for hot Mizaj, while those with higher fat mass than muscle mass have a cold Mizaj score. Thin people are of two types: a thin person with average muscle mass gains a score for hot and dry Mizaj. On the other hand, thinness with little muscle mass will gain score for cold and dry Mizaj (Ansari et al. 2010; Lari and Amin 2013; Parvizi et al. 2016).

Hair Conditions: Hairiness, dark/black hair color, and rapid hair growth are signs of hotness. On the contrary, sparse bright hair and slow hair growth indicate coldness. Indeed, to specify individual differences based on Mizaj, variations in each factor must be considered among people of one race. The difference between races is not a topic of this research (Avicenna 2005).

Skin Color Tone: Within each race, red, yellow, or dark tones are signs of hotness. And bright colors with white and faint hues are signs of coldness. Areas that are not exposed to sunlight should be examined to assess skin color tone (Akhawayni 1992).

Physique: This criterion includes height, frame, size of chest, joints, and extremities as well as pulse parameters. Assessment of pulses to determine the Mizaj needs special training and experience in PM pulsology. Individuals with hot Mizaj usually have a large frame, big chest, square shoulders, large and long limbs, prominent vessels, strong pulse, and large joints. On the contrary, in cold Mizaj, figures, chests, and limbs are small, the superficial veins are non-prominent, the pulse is weak, and joints are small and non-prominent (Harik-Khan et al. 2004).

Impressibility from Hotness, Coldness, Dryness, and Wetness: People with hot Mizaj cannot tolerate heat and are more comfortable in cool weather. Moreover, they cannot tolerate consuming too many warm-natured foods such as some seasonings, pepper, and sweets. On the contrary, cold-mizaj people feel better in hot weather and with warm-natured foods (Majusi Ahwazi 2008).

Sleep and Wakefulness: Oversleeping (more than 10 hours a day) is a sign of coldness, wetness, or both. Some people suffer from too much sleep when they travel to humid areas. A person with a cold-wet Mizaj needs more sleep in such places. Sleeping less (less than 6 hours per day) is usually a sign of hot or dry Mizaj or a combination of both (Azfar et al. 2020).

Functions: All physical, physiological, and psychological functions of the body can signify a person’s Mizaj. Fast, powerful, and optimal physical activities are signs of hotness, whereas, slow, weak, and deficient physical activities are signs of coldness. Hot-tempered individuals have the following characteristics: fast growth of the body and hair, early teething, projected and loud voice, fast, loud, and fluent speech, more powerful, and brisk movements. The hotness of Mizaj sometimes leads to precipitance and hastiness and may result in a lack of resolution in decisions. Cold-tempered individuals, on the other hand, are quieter and slower in their movements (Shahabi and Hassan 2008).

Quality of Waste Matter: Characteristics of secretions and excretory materials, including urine, feces, sweat, and other secretions, can signify Mizaj. The strong color and odor of the secretions mentioned above signify hotness, whereas lighter colors and less odor indicate coldness (Razes 2008).

Mental and Emotional States: Bravery, boldness, anger, risk-taking, hope, intelligence, and talent are signs of hotness, and their opposites are indicative of coldness. Hot-tempered individuals are happier, more talkative, and more quick-minded. They become angry more easily, are courageous, and take more risks. On the contrary, cold-tempered individuals are reserved and tend to keep quiet. They are shy and do not communicate with others easily. They have weaker memories, rarely become angry, are conservative, and seldom take risks (Salmannezhad et al. 2017).

It is worthy to note that the basic “native” behavioral/personality characteristics of a person are used to determine Mizaj. It is not an easy assessment in many cases as most of the adults’ behaviors are acquired and influenced by the training a person received (Aghili Shirazi 2006).

The above-mentioned criteria are used to assess the general Mizaj of the body. However, there are detailed symptomology definitions to determine Mizaj of each organ of the body which is noticed in the clinical setting when a patient complains regarding a special organ rather than systematic symptoms. In PM, the heart, brain, and liver are called chief organs, so, the Mizaj of these organs contributes greatly in signifying the Mizaj of the body (Ansari et al. 2018). For example, sleep is a specific index of brain Mizaj. Skin color is a specific indicator of liver Mizaj and, the pulse is a specific index of heart Mizaj. Thus, it can be claimed that general Mizaj is the sum total of the Mizaj of all body organs, especially, those three mentioned above. Among these organs, the Mizaj of the heart and liver are relatively warmer, and the brain colder (Dar et al. 2011).

Although Mizaj is the sum of the scores of the ten parameters mentioned, diagnosis is not always easy, and there might be some confusion, especially, when signs of hotness, coldness, and moderation all exist simultaneously. As mentioned previously, coldness and hotness are two ends of the spectrum; so, while identifying the two ends of the spectrum with consistent indices is easy, diagnosis of indices near the temperate or inconsistencies in hotness or coldness is complicated and need special training and experience.

8 Factors Affecting Mizaj

Genetically, everyone is born with a unique Mizaj, which can, to some extent, change with factors such as lifestyle, age, season, climate, place of residence, and habits. Mizaj in the beginning years of life is called the primary, main, or innate Mizaj. The Mizaj influenced by environmental factors is called secondary or acquired Mizaj. Therefore, to specify the main Mizaj, the characteristics in childhood and young adolescence should be considered. The influence of the environment on Mizaj is inevitable; thus, when the current conditions of a person are evaluated, the assessed Mizaj is always a secondary one (Aghili Shirazi 2006).

8.1 Age

Variations of physical and mental factors in different ages are justified according to the Mizaj of age groups. Questions such as why children are more agile than adults; why children need to sleep more than adults; why children grow fast; and most physical and mental differences can be explained based on the difference in Mizaj of age groups. Based on PM, age groups are classified into four main categories. From birth until adolescence, especially in the first seven years, growth is faster. Mizaj is in the highest levels of hotness and wetness; as most of the growth occurs in this period. In the 30s and 40s, hotness and wetness are in balance, so, this stage of life is considered the most temperate, with body functions in their best state. Between 40 and 60 years of age, Mizaj gradually becomes colder and drier, and body strength decreases. After the age of 60, there is a gradual decrease in innate heat and innate fluid, resulting in reduced stamina (Avicenna 2005).

8.2 Gender

Men’s Mizaj is hotter and drier than women's. Due to their colder Mizaj, women are more prone to cold diseases, like musculoskeletal and joint disorders (Aghili Shirazi 2006).

8.3 Seasons

In PM, seasons are compared and classified according to their characteristics and are not necessarily coincident with the calendar. Considering that the season affects the body Mizaj, it is necessary to adopt lifestyle changes based on the seasons (Avicenna 2005).

Spring: The Mizaj of this season is in most areas temperate, inclined to hotness and wetness. Warm diseases such as acne, urticaria, and allergies are common in this season. In spring, Persian practitioners (Hakims) suggest avoiding the use of hot seasonings and overuse of warm-natured and blood-producing foods such as meat and soft yolk. Balanced exercise is the best cleansing method, and preventive wet cupping (Hijama) and phlebotomy (Fasd) are recommended for individuals with hot-wet Mizaj (Aghili Shirazi 2006).

Summer: With a hot and dry Mizaj, summer weather induces hotness in the human body, and as a result, signs of heat like the warmness of hands and legs, excessive thirst, and weak digestion appear. Warm diseases, especially in people with hot-dry Mizaj, are more prevalent in this season. Increasing rest-time, consuming cold-natured foods and beverages, using easy to digest foods and avoiding extreme physical activity are recommended in the summer (Avicenna 2005).

Autumn: The Mizaj of autumn is cold and dry. In moderate areas, it is usually cold at night and warm during the day. Due to these climate changes, the body becomes weak, and digestion is impaired. Cold diseases like depression, obsession, and eczema are prevalent in this season. Therefore, it is recommended to consume blood-producing and warm-wet-natured foods such as lamb broth, soft yolk, carrots, figs, and raisins. Engaging in physical exercise to increase hotness and improve digestion is recommended (Aghili Shirazi 2006).

Winter: The Mizaj of winter is cold and wet, especially when it snows. Cold and wet diseases like arthritis, pneumonia, and catarrh are more prevalent at this time. People with hot Mizaj are more refreshed in winter. In winter, internal body temperature increases, so internal organs like the digestion system are stronger during the winter compare to other seasons. Due to this, the consumption of heavy and rich foods, which need more energy for digestion, is permitted. Increased physical activities help to warm up the body. Individuals with cold-wet Mizaj, as well as older women, suffer more from musculoskeletal pains in winter. These individuals usually feel less pain by keeping the home warm and using hot nature drugs and foods such as garlic, black seed, and ginger (Avicenna 2005).

8.4 Region

Land factors such as latitude, wind, vicinity to mountains and seas, soil type, and altitude influence the Mizaj of a region. For instance, mountainous areas increase the coldness of Mizaj, while hot deserts increase hotness (Shirbeigi et al. 2017).

8.5 Foods

Foods have Mizaj and affect the body’s Mizaj as well. The Mizaj of food is usually referred to as their “nature”. The main criterion to identify the nature of foods is based on their effect on the body. Food Mizaj is categorized as hot, moderate, and cold (and based on the secondary qualities to dry, wet, and moderate) (Aghili Khorasani 2009).

Interestingly, food’s nature has a grading system in PM. For example, almond is hot in the first degree/wet in the first degree, while pepper is hot in third degree/dry in the fourth degree. When the degree of a quality is higher than second, it is not considered “food” but rather a “drug”. For instance, pepper is not considered a food, but a drug, as it can change the body Mizaj to a great extent. In other words, based on PM, foods are defined as nutrients that do not change Mizaj dramatically. Substances that are considered drugs, should not be taken regularly without the physicians’ advice as it may lead to Mizaj disturbance (dystemperament) and disease (Aghili Shirazi 2006).

Knowing the nature of foods helps recommend the best dietary advice to people based on their Mizaj. Makhzan al-Advieh is the main reference textbook of PM materia medica describing features of 3413 food and medicines including their Mizaj types and degrees. A database of natural medicinal substances has recently been created from this rich resource using both text mining methods and manual editing (Naghizadeh et al. 2020). Named UnaProd, this database contains common names (in English and Persian), scientific names, and synonyms of medicinal substances in addition to the attributes described in Makhzan al-Advieh, and is also linked to Collective Molecular Activities of Useful Plants (CMAUP) and Iranian traditional medicine General Ontology (IrGO) databases (Naghizadeh Naghizadeh et al. 2019).

Determination of food’s nature can be done based on experiments as well. The main criterion to identify the Mizaj of foods is their function in the body, and the qualities they induce in the body. Moreover, sensible criteria like color and, more importantly, taste can also help identify food’s nature. Based on dominant taste, each food belongs to one of the several Mizaj types (Table 3.2). Some examples of warm foods include lamb, grains like peas and beans, fruits like grapes and raisins, sweet foods, almonds, vegetables like celery, fenugreek, mustard, and dates. Fish, sour foods, cucumbers, sour cherries, tomatoes, lentils, and yogurt are examples of cold foods.

Table 3.2 Identification of food nature based on tastes
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Hot-tempered individuals feel better eating cold foods and fruits but feel uncomfortable taking too much warm foods. For instance, they may experience urticaria, rash, palpitations, or hot flashes upon consumption of honey, dates, and hot spices. In contrast, cold-tempered people feel better eating warm foods and spices. They may suffer from hyper-salivation, bloating, reflux, malaise, and sometimes sleepiness when consuming cold foods (Avicenna 2005).

8.6 Drugs

A cold or hot drug creates a cold or hot change in body Mizaj, respectively, upon entering the body and after undergoing metabolism. The purpose of determining the drug’s nature is to predict how they react in the human body (nature) and how strong is their effect (grade of nature). For example, the black seed is hot in grade 3 and dry in grade 3, so, it can produce more heat in the body than sesame seed which is hot in grade 2 and wet in grade 2. Nature and its grade vary between plants based on their type, growing region, and the consumed parts (seed, leaf, petal, or root). In general, there are four grades for the severity of hotness–coldness. First-grade drugs cause a slight change in Mizaj, even when consumed in large amounts or over a long time. Second-grade drugs induce an evident change in Mizaj following consumption, but not to the point of causing dysfunction. Third-grade drugs produce a huge change in the Mizaj and can lead to a disturbance in body functions. Finally, fourth-grade drugs cause such a huge change accompanied by a severe disturbance that may lead to intoxication (Naghizadeh et al. 2020).

PM specialists consider the patient’s Mizaj deviation degree to decide which grade of drug nature and dosage is needed. For instance, a patient with a cold disease needs hot drugs for treatment, and the level of hotness is determined based on the severity of cold dystemperament. Obviously, if the drug produces more hotness than the person needs, it can cause side effects due to excessive heat (Aghili Shirazi 2006).

When prescribing combined drugs made by mixing different herbs with different Mizaj, traditional pharmaceutical specialists calculate the drug nature based on the amount, dosage, nature and grade of each constituent (Aghili Khorasani 2009).

It should be noted that not all effects of herbal drugs are related to their nature and their effects on the body’s Mizaj. A part of herbal drug function depends on its bioactive compounds aside from their nature. Therefore, drugs can have therapeutic effects for all Mizaj types based on their bioactive compounds (Shirbeigi et al. 2017).

9 Role of Mizaj in Disease Prevention and Treatment

Lifestyle is a strong prevention and treatment tool to both maintain healthy Mizaj (temperament) and modify dystemperament. PM recommendations for health maintenance stand on two principles. The first includes instructions given to all people irrespective of their Mizaj. For instance, refraining from eating when the stomach is full and sleeping early at night. The second group includes recommendations that are tailored based on individualized Mizaj (Avicenna 2005). PM recommendations to maintain optimal health are based on six main principles which are always the first cornerstone in disease prevention and treatment. They are described as follows:

9.1 Climate

In some diseases of dystemperament, changing the living place can modify the Mizaj. For instance, a person with muscle pain aggravated in cold weather or eating cold foods may improve considerably by moving to a hotter climate (Avicenna 2005).

9.2 Food and Drink

Eating warm-natured foods like cinnamon, dates, or honey can sometimes improve some cold-Mizaj disorders. On the contrary, hot-Mizaj individuals feel better if they eat cold-natured foods, such as yogurt or watermelon, and feel irritated if they eat warm-natured foods such as pepper. Therefore, it is recommended that individuals avoid overeating foods that are not in harmony with their Mizaj (Razes 2008).

9.3 Sleep and Wakefulness

Oversleeping can lead to coldness. This is why Persian physicians advise cold-tempered individuals to avoid too much sleep, particularly taking naps during the day. A short nap, of course, is useful for hot-tempered individuals, especially in summer. Sleep deprivation can reduce innate fluid (Rutubat Ghariziyya) and, subsequently, innate heat (Hararat Gharizyya), which in the long-term leads to cold dystemperament (Avicenna 2005).

9.4 Body Movement and Repose

Moderate movement of average intensity and length creates hotness. Therefore, to maintain health, those with cold Mizaj need more exercise. In this regard, quick, strong sports in warm environments are beneficial for cold-tempered individuals. However, a long duration of heavy sport will eventually lead to cold dystemperament. Hot-tempered individuals, however, experience adverse effects from heavy exercise and are recommended less duration and lighter sports. Sports such as skiing or swimming which are done in cold and humid environments are suitable for this group. In conclusion, sports and bodily movements are to be individualized to fit one’s Mizaj (Avicenna 2005).

9.5 Mental and Emotional States

Depression induces coldness, whereas mild happiness and anger create hotness in the body. In recent studies, the relationship between some of the factors noted above with Mizaj has been investigated (Salmannezhad et al. 2017). This is the reason it is advised for elderly patients, who are prone to coldness, to avoid reading bitter, sad news. Social relationships, which have been proposed as a disease protective measure in recent studies, can prevent cold dystemperament in the elderly (Xu 2019).

9.6 Retention of Healthy Matters and Excretion of Waste Matters

Optimal natural excretion of waste matters through urination, defecation, menstruation, sweat, and other ways such as mucus, sperm, hair, and nail are important to maintain health. The excretion ways can be reinforced through exercise, massage, wet cupping, bloodletting, and fasting. These measures can help excrete waste and disease-inducing matters and are prescribed based on an individual’s Mizaj, both as prevention and as treatment. On the other hand, retention is another principle of health, so, one should be careful not to lose healthy matters through natural or induced excretion ways such as excessive diarrhea, bleeding, bloodletting, menorrhagia, vomiting, heavy exercise, and sleep deprivation (Moradi et al. 2017).

9.7 Role of Mizaj in Disease Diagnosis and Classification

According to the PM, a disease is an imbalanced state which leads to impaired organ function. A substantial portion of diseases is the result of dystemperaments, implying loss of healthy Mizaj in either the whole body or an organ that leads to dysfunction (Miraj et al. 2016). In such cases, treatment is achieved by rebalancing the Mizaj state (Aghili Shirazi 2006). Signs of the most prevalent general dystemperaments are listed in Table 3.3.

Table 3.3 Signs of dystemperaments of the whole body
Full size table

9.8 Mizaj Diagnostic Tools

Developing standard diagnostic tools are the cornerstone to conduct clinical research and prepare valid guidelines. Therefore, several efforts have been made to design and validate Mizaj questionnaires (Mirzaeian et al. 2019). Among those, Mojahedi Mizaj Questionnaire (Mojahedi et al. 2014) for 20- to 40-year-old individuals, Salmannezhad Mizaj Questionnaire (Salmannezhad et al. 2018) for 40- to 60-year-olds, and Akhtari Mizaj Questionnaire for 60+ year-old individuals have passed all stages of standard-diagnostic scale development. Currently, preliminary studies are being carried out using these standardized scales to assess the correlation of Mizaj with clinical outcomes, genetic polymorphism, and biological factors (Rezadoost et al. 2016). Considerable psychometric studies to design and validate Mizaj-identification questionnaires for organs including the brain, liver, stomach, uterus, and heart are being carried out in academic research centers in Iran. It is expected that the results of these studies will remarkably transform the scientific community’s understanding of the Mizaj concept.

9.9 Case Discussion

According to the history and examinations, the cause of Sheila’s infertility was diagnosed as cold and wet dystemperament in general, and also in her uterus and stomach which presented with decreased metabolism and weight gain.

As a general rule, an important principle in treating a disease is to restore the patient’s Mizaj to its normal state. To achieve this, the nature of the chosen drug must be opposite to Mizaj of the disease. So, treatment was established with lifestyle modifications according to the six principles of health in the first step, including increased physical activity, eliminating her cold-natured diet, avoiding napping, depression prevention, and keeping the body away from cold. Those all are lifestyle recommendations that deviate the temperament toward hot. Warm-natured medicines such as fennel were recommended to warm the uterine area and regulate menstruation. Bodywork, including cupping on the hypogastric area, was performed to warm her uterus and ovaries by improving circulation, hence, enhancing the medications’ effect. Massaging the hypogastric region with chamomile oil was also recommended. Also, a diet was recommended to the patient using hot-natured foods. After 3 months of treatment, the patient was free of digestive symptoms and lost 8 kg of weight. Menstruation became regular, and she became pregnant in the fourth month. At a follow-up 6 weeks later, the ultrasound showed that the fetal heart had formed.

10 Conclusion

The concept of Mizaj is one of the most important concepts in PM and is defined based on individual differences in phenotypical, psychological, spiritual, and physiological functions. According to this principle, individuals are categorized in terms of two pairs of qualities: hotness–coldness and wetness–dryness. The ten characteristic factors help to diagnose the general Mizaj of the body while there are other specific criteria to determine body organs’ Mizaj. Specific lifestyle recommendations based on Mizaj can promote health and prevent diseases.

With deviation from healthy Mizaj, dystemperament happens which is often accompanied with the imbalance in four humors of black bile, yellow bile, phlegm, and blood. Major types of dystemperaments have their own clinical manifestations and are treated by lifestyle modification and medications that have a Mizaj opposite to the Mizaj of the disease.

With the help of the newly developed Mizaj-identification questionnaires, there have been reports of considerable clinical results, implementing the Mizaj concept into the clinical practice, although more comprehensive studies are needed to reach conclusive results (Akhtari et al. 2020). Integrating the Mizaj-based approach with conventional medical treatment has been shown in several studies to result in more effective disease management. Studies have shown that the PM theory of Mizaj in disease diagnosis and treatment is in accordance with personalized results from omic studies. Several challenges are faced in practicing the individual-based trend of personalized medicine. Using the group-based concept of Mizaj (phenotype identification), this science’s goals may become more practical, reachable, and economical (Jafarnejad et al. 2016; Baradaran-Akbarzadeh et al. 2018; Alibeigi et al. 2020).