What should you know about for hair fall which blood test?

Hair shedding can follow illness, stress, weight change, pregnancy, restrictive eating or some medicines. Blood tests do not diagnose every type of hair loss, so the clinician also asks whether shedding is sudden or gradual, examines the scalp and checks for pattern, broken hairs, inflammation or scarring. A full blood count can look for anaemia, while iron studies assess iron stores. Thyroid tests may be considered when symptoms suggest a thyroid problem. Further testing depends on diet, bowel symptoms, periods, fatigue, kidney health and other findings.

Make an appointment if shedding is persistent, marked or accompanied by scalp changes. Bring a list of medicines, supplements, recent illnesses and dietary restrictions, and note when the change began. Tell the clinician about heavy periods, tiredness, weight change, cold intolerance, bowel symptoms or recent fever. Do not start iron, biotin or other supplements before discussing them; some can affect test interpretation or be unsuitable for you. Gentle hair care can reduce breakage while the cause is assessed.

Arrange prompt assessment for rapidly expanding bald patches, painful or inflamed scalp, pus, heavy scaling, eyebrow or eyelash loss, or hair loss with marked fatigue, weight change or weakness. Seek urgent care for hair loss with severe illness, fainting, unusual bleeding or breathing difficulty. Hair shedding after an illness may improve as the body recovers, but a clinician should check persistent or scarring changes because early treatment can protect follicles.

Ask which tests are relevant to your pattern of loss, whether you need iron or thyroid testing, and when results should be reviewed. Discuss whether a scalp examination or dermatology referral is needed. Mention recent infections, travel, digestive symptoms and any treatment already tried. Related reading includes [Anaemia](/conditions/anaemia/), [Coeliac Disease](/conditions/coeliac-disease/) and [Chronic Kidney Disease](/conditions/chronic-kidney-disease/).