The Root Causes of Hair Loss

Hair loss is rarely caused by a single factor. In most patients Dr. Ashwini sees at Sapphire Roots, it is the result of multiple interacting causes — a genetic predisposition combined with a hormonal imbalance, compounded by nutritional deficiencies, and aggravated by stress. Understanding which causes are at play for you is essential for effective, targeted treatment.

80%
of male hair loss is genetic
40%
of women affected by age 40
90%
of cases are treatable

1. Genetics & DHT (Androgenetic Alopecia)

Genetics is the single most common cause of hair loss in both men and women. Androgenetic alopecia affects an estimated 80% of men and 40% of women at some point in their lives.

The condition is driven by dihydrotestosterone (DHT) — a potent androgen derived from testosterone via the enzyme 5-alpha reductase. In genetically susceptible individuals, DHT binds to hair follicle receptors and causes progressive miniaturisation — each generation of hair becoming thinner, shorter, and lighter, until the follicle stops producing visible hair.

The genetic vulnerability is polygenic — inherited from both parents. The old belief that baldness comes only from the mother's side is a myth.

💡 Key Insight

If your father, grandfather (either side), or maternal uncles experienced significant hair loss, your risk is elevated. But risk is not destiny — with early intervention, androgenetic alopecia can be managed, slowed, and surgically corrected.

Treatments for Genetic Hair Loss

  • Finasteride: Inhibits 5-alpha reductase, reducing DHT by ~70%. Proven to halt progression in ~85% of men. Requires lifelong use.
  • Minoxidil: Topical or oral vasodilator that extends the anagen phase. Works in both men and women.
  • Hair Transplant (FUE/DHI/Sapphire FUE): The only permanent solution — transplanting DHT-resistant follicles from the donor zone to thinning areas.
  • PRP/GFC Therapy: Stimulates miniaturised follicles in early-stage androgenetic alopecia.

2. Hormonal Causes

  • DHT: The primary driver of androgenetic alopecia in both men and women. Even at normal testosterone levels, increased follicular sensitivity to DHT can cause female pattern hair loss.
  • Thyroid Hormones: Both hypothyroidism and hyperthyroidism cause diffuse hair loss. A simple TSH blood test screens for thyroid dysfunction — one of the most important first investigations.
  • Oestrogen & Progesterone: These have a hair-protective effect, prolonging the anagen phase. Their dramatic drop after childbirth, during perimenopause, or after stopping the pill triggers postpartum or hormonal telogen effluvium.
  • PCOS: Polycystic Ovary Syndrome — elevated androgens and insulin resistance directly drive female pattern hair loss, often causing significant thinning in women in their 20s and 30s.
  • Prolactin: Elevated prolactin (hyperprolactinaemia) from pituitary tumours or medications can suppress ovarian function and trigger hair loss in women.

3. Nutritional Deficiencies

Hair follicles are among the most metabolically active cells in the body, requiring constant nutrients. Deficiencies are a frequently overlooked but highly treatable cause:

  • Iron Deficiency: The most common nutritional cause, particularly in premenopausal women. Even sub-clinical deficiency (low ferritin with normal haemoglobin) can cause significant hair loss. Target ferritin >70 ng/mL for optimal hair growth.
  • Vitamin D: Receptors found in hair follicles play a role in the hair cycle. Deficiency is strongly linked to alopecia areata and telogen effluvium. Most Indians are commonly deficient.
  • Zinc: Essential for DNA replication and cell division in follicles. Deficiency causes diffuse hair loss and is associated with alopecia areata.
  • Protein: Hair is primarily keratin protein. Inadequate dietary protein — from crash dieting or restrictive diets — causes significant shedding.
  • Vitamin B12 & Folate: Deficiencies (common in vegetarians) impair red blood cell production and reduce oxygen delivery to follicles.
🔬 Our Diagnostic Approach

Dr. Ashwini typically recommends a blood panel including: CBC, ferritin, serum iron, TIBC, thyroid function (TSH/T3/T4), vitamin D, B12, zinc, fasting insulin, and androgens. This comprehensive screening identifies treatable causes quickly and guides targeted treatment.

4. Stress — Physical & Psychological

The characteristic feature of stress-related hair loss (telogen effluvium) is its delayed onset: shedding typically begins 2–4 months after the stressful trigger — not immediately. This confuses many patients who cannot connect their hair loss to its actual cause.

Common triggers include: major surgery, severe illness (including COVID-19), rapid weight loss, bereavement, divorce, major life upheaval, and post-pregnancy hormonal changes.

The good news: telogen effluvium from an identifiable, resolved trigger is usually temporary. Most patients see significant regrowth within 6–12 months. However, if hair loss persists beyond 6 months, or there is an underlying genetic predisposition, medical treatment may accelerate recovery.

5. Medical Conditions

  • Alopecia Areata: Autoimmune — the immune system attacks follicles, causing unpredictable patchy hair loss.
  • Scalp Infections: Tinea capitis (fungal), folliculitis (bacterial), and other infections can damage follicles.
  • Lupus (SLE): Frequently causes diffuse thinning and, in some cases, scarring alopecia.
  • Psoriasis & Seborrheic Dermatitis: Inflammatory scalp conditions that, when severe, can damage follicles.
  • Anaemia: Chronic anaemia from any cause reduces oxygen delivery to follicles.
  • Diabetes: Impairs circulation and nutrient delivery to follicles; associated with accelerated androgenetic alopecia.

6. Medications That Cause Hair Loss

  • Blood thinners (warfarin, heparin): Can cause telogen effluvium with prolonged use
  • Beta-blockers: Used for blood pressure/heart conditions — associated with diffuse hair loss
  • Antidepressants (SSRIs, SNRIs): Some patients experience hair loss, particularly in initial months
  • Oral contraceptives: Can trigger hair loss during use or upon stopping (withdrawal telogen effluvium)
  • Statins: Cholesterol medications — associated with hair thinning in some patients
  • High-dose retinoids (vitamin A derivatives): Well-documented cause of hair loss
  • Chemotherapy: Causes anagen effluvium — rapid hair loss during growth phase. Usually reverses after treatment.
⚠️ Important

Always consult your prescribing doctor before stopping any medication. Drug-induced hair loss is often reversible once the medication is adjusted — but stopping without medical guidance can be harmful to your overall health.

7. Hair Care & Styling Damage

  • Tight hairstyles: Braids, weaves, tight ponytails, and buns — constant tension causes traction alopecia, which can become permanent
  • Heat damage: Flat irons, curling wands, and hair dryers at high temperatures damage the hair shaft and, long-term, follicle health
  • Chemical processing: Bleaching, perming, and relaxing treatments — harsh on hair and scalp; repeated treatments cause cumulative damage
  • Heavy extensions: Place significant traction on natural follicles and can cause permanent damage if worn continuously

Frequently Asked Questions

Can wearing a helmet cause hair loss?
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Wearing a helmet does not directly cause hair loss. Poorly fitting helmets can cause traction and friction damage. More importantly, helmets cause scalp sweating and heat — if the scalp is not kept clean, this can worsen dandruff and scalp conditions that indirectly affect hair health.
Does hard water cause hair loss?
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Hard water can make hair more brittle and prone to breakage, but does not directly cause follicular hair loss. The minerals coat the hair shaft and interfere with shampoo/conditioner absorption. A chelating shampoo used weekly can significantly reduce this effect.
Is hair loss from COVID-19 permanent?
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Post-COVID hair loss (telogen effluvium triggered by the stress of illness) is typically temporary. Most patients see significant regrowth within 6–12 months. However, if you had an underlying predisposition to androgenetic alopecia, COVID-19 may have accelerated it — in which case medical treatment or hair transplant may be appropriate.