Quick answer: Most hair loss has a treatable root cause, not just genetics. The 10 most common causes seen at Mister Hair are DHT sensitivity (pattern hair loss), iron/ferritin deficiency, thyroid imbalance, stress-driven shedding (telogen effluvium), nutritional gaps, scalp conditions, hormonal shifts, harsh hair practices, medications, and poor sleep. A root-cause analysis identifies which one is driving your shedding before any treatment begins.
Treating hair loss without knowing the cause is guesswork. At Mister Hair, every case starts with a structured root-cause analysis — blood markers, scalp evaluation and history. These are the ten causes we see most often.
- DHT sensitivity (pattern hair loss). The hormone DHT shrinks genetically sensitive follicles until they stop producing hair. It’s the most common cause in men and a major one in women, and it’s progressive — which is why early action matters most.
- Iron & ferritin deficiency. Low iron stores are one of the most overlooked causes, especially in Indian women. Hair sheds diffusely across the scalp and often reverses once ferritin is corrected.
- Thyroid imbalance. Both an under- and over-active thyroid push follicles into the shedding phase. A simple blood panel catches it, and treating the thyroid usually settles the hair.
- Stress-driven shedding (telogen effluvium). A physical or emotional shock — surgery, illness, grief, crash dieting — pushes many follicles into rest at once, causing heavy shedding 2–3 months later. It’s usually temporary.
- Protein, vitamin D & B-vitamin gaps. Hair is built from keratin protein; chronic shortfalls in protein, vitamin D, zinc or B-vitamins starve the follicle. Vegetarian and high-restriction diets are common culprits in India.
- Scalp conditions. Dandruff, seborrheic dermatitis and fungal infections inflame the scalp and weaken the follicle’s anchor. Treating the scalp often slows shedding on its own.
- Hormonal shifts (PCOS, postpartum, menopause). Pregnancy, childbirth, PCOS and menopause swing the hormones that govern the hair cycle, triggering visible loss — frequently reversible with the right support.
- Harsh hair practices. Tight hairstyles, frequent heat, chemical straightening and over-colouring cause traction and breakage that mimic hair loss but are mechanical damage.
- Medications & medical treatments. Certain blood-pressure drugs, antidepressants, retinoids and chemotherapy list hair shedding as a side effect. Knowing this prevents unnecessary panic and mistreatment.
- Poor sleep & lifestyle load. Chronic sleep debt and high cortisol disrupt the growth cycle over time. It’s rarely the sole cause, but it amplifies every other one on this list.
Frequently asked questions
Can hair loss be reversed?
Often yes, if the follicle is still alive and the root cause is treated early. Pattern hair loss can be slowed and partially regrown; deficiency- and stress-related loss is frequently fully reversible.
How do I find out the cause of my hair loss?
A root-cause analysis — a blood panel plus scalp examination — is the only reliable way. You can book a free hair test at misterhair.in/hairtest.
→ Find your root cause: book a free hair test
Medically reviewed by Dr. Saranya Thulasidoss, MBBS, MCh (Plastic Surgery), Clinical Lead, Mister Hair. Last updated 2026.
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