Most women's hair loss has a cause that can be found, and more than one cause at once is common. For example, low iron plus female pattern thinning, or thyroid disease plus shedding after an illness. That's why working out the cause comes before choosing a shampoo, oil or medicine.
Quick start: answer 14 questions in our cause finder to see which causes match you, and which tests to ask for.
Three questions that narrow it down
- Is hair falling out from the root, or breaking? Shed hairs often have a small white bulb at the end. Broken hairs don't.
- Is it all over, or in a pattern? All-over shedding points to telogen effluvium, deficiencies or thyroid. A widening parting points to female pattern hair loss. Round patches point to alopecia areata.
- When did it start, and what happened 2–4 months before? Delivery, fever, surgery, crash dieting and major stress all cause shedding that starts months later.
The 9 causes at a glance
| # | Cause | Typical pattern | Timing | Clues | Guide |
|---|---|---|---|---|---|
| 1 | Female pattern hair loss | Widening parting, thinner on top; front hairline usually stays | Gradual, over years | Family history; thinner ponytail | Read |
| 2 | Telogen effluvium (shedding after a trigger) | All over; lots of hairs in comb and shower | Starts 2–4 months after a trigger | Fever, typhoid, dengue, COVID, surgery, crash diet, stress, new medicine | Read |
| 3 | After delivery | All over, often most noticeable at the temples | Starts 2–4 months after birth | Recent baby; usually settles within a year | Read |
| 4 | Low iron (ferritin) | All over thinning | Gradual | Tiredness, breathlessness, heavy periods, vegetarian diet | Read |
| 5 | Thyroid problems | All over; sometimes the outer eyebrows thin | Gradual or sudden | Tiredness, weight change, feeling cold or hot, dry skin | Read |
| 6 | PCOS / high androgens | Thinning on top and at the parting, like female pattern | Gradual | Irregular periods, acne, facial or body hair, weight gain | Read |
| 7 | Alopecia areata | Round, smooth bald patches | Sudden | Patches can appear on eyebrows, too | Read |
| 8 | Dandruff / seborrhoeic dermatitis | Shedding with an itchy, flaky scalp | Comes and goes | Flakes, oily scalp, itch | Read |
| 9 | Breakage and traction | Short broken hairs; thinning at the hairline or where hair is pulled | Gradual | Tight buns or braids, heat styling, colouring, rebonding, keratin | Read |
Also consider: menopause (hormonal thinning), medicines (some contraceptive pills, acne medicines, blood thinners, chemotherapy), vitamin D or B12 deficiency, and rarer scarring alopecias. Scarring alopecias show red, itchy or shiny skin where hair has gone, and need a dermatologist quickly. → Vitamin deficiencies
Tests your doctor may suggest
| Test | Checks for |
|---|---|
| CBC + serum ferritin | Anaemia and iron stores (ferritin can be low even with normal haemoglobin) |
| TSH (± free T4) | Thyroid |
| Vitamin D, B12 | Deficiencies, common in India |
| Testosterone, DHEA-S (± other hormones, pelvic ultrasound) | PCOS / high androgens, if you have signs |
| Scalp examination (dermatoscopy) ± biopsy | Pattern loss, alopecia areata, scarring alopecias |
Before tests: stop biotin supplements a few days beforehand (ask your doctor), because high doses can distort some results, including thyroid tests.
Myths
- "It's just stress." Stress can trigger shedding, but persistent thinning deserves a check for iron, thyroid and hormones.
- "Oiling will stop hair fall." Oiling can reduce breakage and dryness. It can't fix low iron, thyroid disease or PCOS.
- "Hard water causes baldness." Hard water can make hair dry and prone to breakage. It doesn't cause pattern hair loss. → Hard water and hair fall
- "Shampooing every day makes hair fall." You see the hairs that were already shed. Washing doesn't increase loss.
See a doctor soon if you have: round bald patches that appear suddenly · hair coming out in clumps · redness, pain, pus, scaling or scarring on the scalp · hair loss with fever, weight loss, irregular periods, acne or new facial hair · eyebrow or eyelash loss · hair loss in a child.
Medical review pending: not yet reviewed by a dermatologist. Medical disclaimer
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