Hair: The Crown of the Head and a Mirror of Temperament, Hormones and Thyroid

Farzollah Gholizadeh and Fariba Bayrami

What can the colour, thickness, growth rate, shedding, early greying and damage of your hair tell us about your temperament, your hormones and your inner health?

Introduction: is hair the brain’s chimney smoke, or where heat and temperament sprout?

To the human eye, hair is a symbol of beauty, youth and vitality. But for the scholars of traditional humoral medicine, such as Ibn Sina (Avicenna) in The Canon of Medicine, Sayyid Ismail Jurjani in Dhakhira-i Khwarazmshahi and Aqili Khorasani in Makhzan al-Adwiya, hair is one of the body’s “useful residues”. It forms from fine, smoke-like vapours left over from the digestion of the humours in the liver and stomach, which rise upwards and condense at the roots of the scalp. In the physicians’ words, hair is like the leaves and branches of a plant fed from its root (the follicle). Its condition reflects the quality of digestion, the work of the liver, the body’s innate heat and the balance of the four humours throughout the body.

Modern medicine confirms many of these observations through endocrinology, the hair growth cycle (anagen, catagen, telogen), genetics, follicular pathology and research on the scalp microbiome. Hair loss, breakage, split ends, early greying or an overly oily scalp are never only a local problem. More often they signal an inner imbalance, chronic stress, a thyroid disorder or a nutritional deficiency.

This in-depth article looks at every side of hair health: the types of hair loss (alopecia), dandruff, early greying, hormonal axes, the role of the scalp microbiome, and practical measures suited to each temperament.

A note on method: linking a hair problem to a particular humour is the theoretical framework of traditional humoral medicine. No hair loss or change in the hair is enough on its own for a firm diagnosis, and this article never replaces a medical examination, blood tests or treatment by a specialist.

1. The temperament science of hair and the four humours

Hair’s feel, colour, thickness and growth rate are shaped by the dominant humour and by the heat of the head:

• Balanced temperament: soft, flexible hair, neither very thick nor very thin, with a balanced colour (chestnut or medium black) and a good growth rate.
• Hot temperament (bilious/safravi or sanguine/damawi): hair is usually thick, coarse, dark or slightly reddish. Because of the high heat it tends towards split ends, dry strands or an early oily scalp.
• Cold and moist temperament (phlegmatic/balghami): hair is thin, soft, sparse, pale or light-coloured, and grows slowly. The scalp is cold and moist, and the roots are weak because of the cold.
• Cold and dry temperament (melancholic/sawdawi): hair is dry, coarse, curly, dull and brittle, and prone to heavy shedding or early greying. The dryness of black bile (sawda) narrows the hair root and blocks its nourishment.

The heat of the head and rising vapours

Traditional texts say the brain is cold and moist by nature, but the head has a suitable warmth because it is close to the principal organs and receives fine vapours. If the vapours rising from the stomach and liver are too hot or foul (burnt or thick vapours), they irritate the hair root and cause hair loss, itching or dandruff.

2. An expert look at the types of hair loss (alopecia): the four humours and where on the head hair is lost

Modern medicine divides hair loss broadly into scarring (irreversible) and non-scarring (reversible) types. From the point of view of humoral medicine, the dominance of each of the four humours not only changes the quality of the hair but also creates a distinct pattern of loss in different areas of the head, depending on how vapours rise and how heat and cold are distributed. These patterns are as follows.

A) Bilious hair loss (hot, sharp, mainly at the front of the head)

• Pattern on the head: when yellow bile (safra) dominates, with its hot and dry nature and light, rising vapours, hair is usually lost at the front of the head, the temples and the hairline (frontal thinning or baldness). The high heat of bile “burns” the hair roots in this area, and it often comes with an oily scalp.
• Clinical features: sudden or patchy hair loss (similar to alopecia areata), with heat, burning or itching of the scalp, oiliness and small spots on the scalp. The hair becomes thin and dry.
• Modern and hormonal background: free-radical damage, follicular inflammation and high androgen activity (such as DHT) against a background of oxidative stress, which makes the hair roots at the front of the head more sensitive.
• Traditional background: dominance of yellow bile, or of burnt bile and black bile, “burning” the hair root with heat and sharpness. Very spicy food, fried food and sharp spices make it worse.

B) Sanguine hair loss (general, “full-blooded”, mainly at the centre and crown)

• Pattern on the head: dominance of the blood humour (dam: hot and moist) comes with high blood flow and full vessels. Here hair loss usually starts at the centre of the head (the crown or vertex) and the top of the head, and spreads from there. The scalp is often red and warm, with thick hair at the sides and thinner hair on top.
• Clinical features: thick hair that tends to shed at the centre of the head, with a feeling of heaviness in the head, full veins at the temples, and facial flushing with heat or excitement.
• Modern and hormonal background: build-up of inflammatory factors and stimulating hormones in the follicles of the crown, linked to high blood flow and metabolism.
• Traditional background: fullness and dominance of blood (imtila); hot, moist vapours, heavier than those of bile, rise and press on the centre of the head, loosening the roots. Overeating and fatty, heavy food make it worse.

C) Phlegmatic hair loss (cold, diffuse and puffy, from the forehead and temples to the back of the head)

• Pattern on the head: dominance of phlegm (balgham: cold and moist) slows capillary blood flow across the whole scalp through heaviness and cold. In phlegmatic people hair loss is usually diffuse and general (from the forehead to the nape). The hair gradually thins and loses body, and the scalp is soft, cold and sometimes puffy (oedematous).
• Clinical features: thin, limp, sparse hair with weak roots that pull out easily. The scalp is cold and moist; the person may have a puffy, heavy head and feel sleepy.
• Modern and hormonal background: slow capillary circulation in the scalp, an underactive thyroid (hypothyroidism), and build-up of interstitial fluid and lymph in the tissue under the scalp.
• Traditional background: dominance of raw, sticky phlegm that blocks the flow of nutrients to the follicles. Lots of cold dairy, ayran (yoghurt drink), cucumber, watermelon and cold water make it worse.

D) Melancholic hair loss (dry, chronic, scattered, with early greying)

• Pattern on the head: dominance of black bile (sawda: cold and dry) comes with density and dryness. In melancholic people hair loss is usually scattered, chronic and progressive over the whole head (especially the temples and the nape). The hair becomes very dry, brittle and frizzy, and early greying is one of its clearest signs.
• Clinical features: dry, coarse, brittle, sparse and thin hair, with dry dandruff and early greying. The scalp is dry, tight and lacks elasticity.
• Modern and hormonal background: early ageing of the follicle, chronic stress (raised cortisol), long-term poor nutrition and seriously impaired circulation in the scalp’s capillaries.
• Traditional background (black bile sediment): thick, burnt black bile concentrated in the blood, which completely blocks the hair’s route of nourishment. Melancholic thoughts, chronic constipation and lack of sleep make this type worse.

E) Alopecia areata (da’ al-tha’lab, patchy hair loss)

• Modern medicine: an autoimmune disease in which white blood cells mistakenly attack the hair follicles, causing round, completely smooth bald patches.
• Humoral medicine: the physicians attributed it to thick phlegm or malignant black bile gathering in one area and blocking the hair’s nourishment.

F) Hormonal and genetic hair loss (androgenetic alopecia)

This is the most common cause of hair loss in men and women. It is driven by the conversion of testosterone to dihydrotestosterone (DHT) by the enzyme 5-alpha reductase. In women, hormonal hair loss together with chin acne, irregular periods and excess body hair suggests polycystic ovary syndrome (PCOS).

3. Dandruff (seborrhoea) and itchy scalp

Modern medicine: dandruff results from overgrowth of the yeast Malassezia, sebum produced by the oil glands and an inflammatory reaction of the scalp. It appears in two forms: dry dandruff (small white flakes) and oily dandruff (sticky yellow flakes).

Humoral medicine:

• Oily dandruff: comes from oily phlegm or bile mixing with hot vapours from the liver.
• Dry dandruff: comes from dominance of black bile, severe dryness of the scalp and reduced natural sebum.

4. Early greying (shayb)

Modern medicine: hair turns grey when the melanocytes in the follicle stop producing melanin (hair pigment). This is normal with age, but early greying is linked to oxidative stress, vitamin B12 deficiency, copper, zinc, genetics and thyroid disorders.

Humoral medicine: the physicians saw early greying as a sign of dominant cold and raw moisture (phlegm), or of dryness and burning of the humours (burnt black bile), which weakens the innate heat of the hair root and its ability to make pigment.

5. Hormones, thyroid and nutrition in hair health

• Thyroid and hair: an underactive thyroid makes hair dry, coarse and thin, causes diffuse shedding and slows nail growth; an overactive thyroid makes hair thin, brittle and prone to falling out. The thyroid should be checked in any case of chronic hair loss.
• Iron-deficiency anaemia (low ferritin): iron is vital for carrying oxygen to the follicles. Anaemia is one of the most common causes of diffuse hair loss in women.
• B vitamins and zinc: they play a key role in cell division in the hair matrix and in making keratin.

6. The scalp microbiome and the harm of harsh cleansers

Just as the skin of the body has a beneficial microbiome, the scalp has a delicate ecosystem of bacteria and fungi whose balance prevents dandruff and inflammation.

• Damage from harsh cleansers: constant use of shampoos with strong sulphates (SLS and SLES) and parabens, chemical dyes and hot straighteners strips the scalp’s protective natural oil (sebum) and its beneficial flora. This damages the scalp’s barrier and sets the stage for heavy hair loss, itching and chronic inflammation.
• Traditional view: the physicians stressed washing the hair gently with natural cleansers such as sidr (jujube leaf powder), marshmallow root and washing clay (Armenian clay or natural hair-washing clay). These strengthen the roots and balance the heat of the head.

7. How often to bathe and how to wash your hair

• Traditional view: frequent, long, hot baths drain the natural moisture of the brain and head, leading to dryness, breakage and hair loss. Baths should be moderate and taken with lukewarm water.
• Modern, practical view: over-washing removes the hair’s natural oil. For most people, washing gently two to three times a week with a suitable shampoo is ideal. Avoid scratching the scalp hard with your nails, so you do not damage the follicles.

8. Oiling the hair and scalp for each of the four temperaments

Nourishing the hair shaft and root locally with pure plant oils is one of the finest traditions of humoral medicine, and the oil should be chosen to suit the temperament:

• Bilious (hot and dry: dry hair prone to split ends, warm scalp): needs cold and moist oils to balance the heat: sweet almond oil, violet oil and rose oil.
• Melancholic (cold and dry: coarse, brittle, frizzy hair with dry dandruff): needs warm and deeply moistening oils to relieve the dryness: black seed oil, sesame oil, pure olive oil and bitter almond oil.
• Phlegmatic (cold and moist: thin, weak hair, cold scalp): needs warm and dry oils to stimulate capillary circulation: rosemary oil, chamomile oil or black seed oil (a gentle massage before bathing).
• Sanguine (hot and moist): does not need heavy oiling; if needed, use a little sweet almond oil.

Safety note: oiling too much, or leaving heavy oils on an oily scalp for a long time, can block pores and make hair loss worse. Oil according to your scalp’s needs, before bathing. Use essential oils such as rosemary only well diluted in a carrier oil.

9. Henna and sidr for strengthening and cleansing the hair

In traditional medical texts, two plants have a special place in hair health and hygiene:

• Sidr (jujube leaf, Ziziphus spina-christi): cold and moderate in temperament. Sidr strengthens the hair, removes excess oil from the scalp, cleanses it and helps prevent hair loss caused by heat and bile.
• Henna: besides its colouring properties, henna contains polyphenols and tannins that strengthen the hair’s protein (keratin), help with split ends, strengthen the roots and regulate scalp oil. Pure henna with no chemical additives is very effective for strengthening oily and normal hair. Avoid “black henna”, which contains a chemical dye (PPD) that can cause severe allergic reactions.

10. Principles of hair care, nutrition and prevention from humoral and modern medicine

• Repair digestion and eat well: because hair is nourished by the residues of the liver’s digestion, avoiding fast food, heavy meals, trans fats and constipation is the foundation of healthy hair growth. Include nuts (almonds and walnuts), fresh vegetables, pulses and good-quality protein in your diet.
• Manage stress and sleep enough: high cortisol from chronic stress lengthens the hair’s resting phase (telogen) and causes heavy shedding.
• Protect your hair physically: avoid tying it very tightly (this causes traction alopecia), cut down on hot tools (hot hair-dryers, straighteners) and avoid frequent chemical colouring.

Conclusion

Human hair is not just lifeless decorative tissue. It is a sensitive indicator of the body’s inner dynamics, hormonal balance, thyroid health and humoral balance. The real remedy for hair loss, breakage and early greying never comes from expensive topical shampoos or superficial promises. It requires repairing digestion, balancing hormones, choosing oils that suit your temperament, avoiding harsh chemicals, and using traditional natural cleansers such as sidr and henna.

To understand your own temperament better, take our free temperament test and read our article on the six rules of health.

References

• Ibn Sina (Avicenna). Al-Qanun fi al-Tibb (The Canon of Medicine). Sections on natural matters, temperaments and diseases of the hair (hair loss, alopecia areata, greying and baldness).
• Jurjani, Sayyid Ismail. Dhakhira-i Khwarazmshahi. Section on assessing the hair and outward signs of diseases of the head and skin.
• Aqili Khorasani, Sayyid Muhammad Husayn. Makhzan al-Adwiya. Properties of remedies: henna, sidr, beneficial oils for the hair and strengthening the roots.
• Bolognia JL, Schaffer JV, Cerroni L. Dermatology. 4th ed. Elsevier; 2018.
• Kang S, Amagai M, Bruckner AL, et al. Fitzpatrick’s Dermatology. 9th ed. McGraw-Hill; 2019.
• Trueb RM. The difficult hair loss patient: etiology, diagnosis, and management. Expert Review of Dermatology. 2009;4(4):393-406.
• American Academy of Dermatology Association. Hair loss: diagnosis, types, and treatment guidelines.
• DermNet NZ. Resources on hair disorders, alopecia and scalp conditions.
• Gholizadeh Kalan F, Bayrami F. İnsan Mizaçları ve Sağlıklı Beslenme (Human Temperaments and Healthy Nutrition). İzmir: Memento Mori Yayınları; 2024.
• Gholizadeh Kalan F. Sağlığın 6 Altın Kuralı (The Six Golden Rules of Health). Ankara: Dr Kalan Natural; 2022.
• Gholizadeh Kalan F. Mizacın Sırları (The Secrets of Temperament). Ankara: Dr Kalan Natural; 2026.
• Gholizadeh Kalan F. Elaim & Delail (Signs and Indications). drkalan.com.