What should you know about hair fall related blood test?

Hair shedding may be linked with a recent infection, nutritional deficiency, hormonal change, chronic illness, medication or physical stress. A clinician chooses tests according to the story rather than ordering every available test. Blood work may assess blood cells, iron-related status, thyroid function, kidney function or other clues to illness.

Conditions such as anaemia, coeliac disease, Crohn's disease and chronic kidney disease can have symptoms beyond the hair. Brucellosis, dengue fever or glandular fever may also be considered when the illness history and examination support them. A blood result alone does not establish the cause of hair fall.

Describe whether hairs are shedding from all over the scalp or forming distinct patches. Mention recent fever, surgery, rapid weight change, stress, new medicines, restrictive eating and family patterns of hair loss. Bring a complete list of medicines and supplements, and ask whether any preparation is needed. Keep taking prescribed treatment unless the ordering clinician gives different instructions.

Book a clinical assessment for sudden or progressive loss, patchy bald areas, scalp inflammation or loss of eyebrows or body hair. Seek prompt care when hair fall accompanies persistent fever, severe tiredness, fainting, shortness of breath, swollen legs, ongoing diarrhoea or reduced urination. Urgent symptoms should not wait for a routine hair investigation.

What conditions are you checking for, and why? Which results would change management? Should I have a scalp examination or specialist review? Could a recent illness explain the timing of shedding?