Hair fall
Hair fall: the common causes, the tests that find them, and what helps
Updated 12 October 2026
Losing up to 100 hairs a day is normal. Hair fall is when you lose clearly more than that for several weeks, or when the hairline, parting or crown looks thinner.
Most hair fall has a cause that can be found and fixed. A shampoo alone rarely fixes it; finding the cause does.
The common causes
- A shock to the body two to three months ago: fever, illness, surgery, childbirth, crash dieting or major stress. Hair sheds all over; the shedding usually settles within six months, and the hair fills back in over the following months.
- Low iron, vitamin D or vitamin B12. Very common in India, especially in women.
- Thyroid problems, either under- or over-active.
- PCOS and other hormone changes: thinning at the parting, with acne or irregular periods.
- Pattern hair loss (genetic): a receding hairline or thinning crown in men, a widening parting in women.
- Dandruff and scalp inflammation.
The tests that help
A blood test for haemoglobin, ferritin (stored iron), vitamin D, vitamin B12 and thyroid finds the most common fixable causes. Women with irregular periods or acne should add hormone tests for PCOS.
What helps while you find the cause
- A gentle shampoo, two or three times a week; an anti-dandruff shampoo if you have flakes.
- Supplements only for what a test shows you are low in. Extra biotin does not help if you are not deficient.
- Protein in every meal.
- For pattern hair loss, minoxidil and other prescription treatments work best started early, with a dermatologist's advice.
