What should you know about blood test to check hair loss?

The tests chosen depend on your pattern of hair loss, medical history and examination. A clinician may consider a blood count, iron-related checks, thyroid testing or other tests when symptoms suggest them. Hair loss can also follow illness, stress, hormonal changes, scalp inflammation, inherited patterns or certain medicines, which blood tests may not detect. A normal result does not mean the concern is imaginary; it helps narrow the next step.

Describe when shedding began, whether it is sudden or gradual, and whether you have itching, scaling, weight change, heavy periods or recent illness. List medicines and supplements, including products marketed for hair growth. Ask if fasting is needed. Avoid starting high-dose supplements before discussing them, because they can affect health and sometimes interfere with testing. A scalp examination may be as useful as blood work.

Arrange prompt medical review for rapidly spreading loss, smooth bald patches, scalp pain, pus, marked redness, or loss of eyebrows or eyelashes. Seek urgent help if hair loss occurs with facial swelling, breathing difficulty or a severe allergic reaction. Otherwise, book a routine assessment when shedding persists or is distressing.

Which causes fit my pattern? Which tests are you recommending and why? Could a medicine or recent illness be involved? Should I see a dermatologist if the result is normal?