Testosterone testing for hair loss

A blood test measures testosterone at one point in time. Results need context because hormone levels vary with timing, medicines, supplements, health conditions, and the laboratory method. A result by itself does not identify the cause of hair loss or show how sensitive an individual follicle is to androgens.

Testing is more likely to be considered when scalp thinning appears with irregular periods, new acne, increased facial or body hair, or other signs of androgen excess. A widening part can fit female pattern hair loss, but telogen effluvium, alopecia areata, scalp ringworm, and traction alopecia follow different patterns and may not call for testosterone testing.

Before the appointment, record when shedding began, whether it is diffuse or patchy, recent illness or major stress, changes in periods, and every medicine or supplement you use. Bring information about pregnancy possibility and hormonal contraception. Your clinician may combine a scalp examination with selected blood tests, such as tests related to iron or thyroid function, when your history suggests them.

Do not alter prescribed hormones or begin a hair-loss medicine to change the result. Ask whether the sample needs a particular timing or whether a repeat test is appropriate if the result does not match your symptoms.

Arrange prompt care for rapidly progressing loss, smooth bare patches, scalp inflammation, pus, heavy scale, or painful areas. Seek timely evaluation when hair loss accompanies voice deepening, sudden increased facial hair, severe acne, or a significant menstrual change. Fever with a tender, swollen, or spreading scalp needs urgent attention.

Ask why testosterone testing is being considered, what other causes are being checked, how medicines may affect interpretation, and what the next step will be for a high, low, or expected result. Ask whether your scalp pattern needs treatment even if the test is within the expected range.