What should you know about hair fall blood test?

A clinician may use blood work when hair shedding is widespread, sudden, persistent or accompanied by fatigue, weight change, bowel symptoms or changes in the menstrual cycle. The choice of tests depends on your history. A full blood count can help assess anaemia, while other tests may examine thyroid function, nutrient status, kidney function or signs of inflammation.

Hair fall can follow illness, major stress, hormonal change, medication or a scalp disorder. Blood results may be normal even when shedding is real, and an abnormal result does not prove it is the only explanation. The pattern of loss and scalp findings remain important.

Note when shedding began, whether it followed an illness or dietary change, and whether the loss is diffuse, patchy or concentrated at the hairline. List medicines, supplements and recent treatments. Follow the laboratory's instructions about fasting or usual medicines, and do not start high-dose supplements before testing unless a clinician advises it, because they can affect some results.

Arrange a review for rapidly increasing loss, smooth bald patches, scalp pain, scaling, redness or pus. Seek prompt care if hair fall occurs with severe fatigue, fainting, persistent fever, swelling or marked changes in urination. These associated features may point to a wider health problem that needs examination rather than a hair-focused test alone.

Which blood tests fit my pattern of loss? Do I need a scalp examination or dermatologist referral? Could my medicines or recent illness be involved? When should results be reviewed?