Hypothyroidism and loss of eyebrows: what to know

Low thyroid hormone can alter the hair-growth cycle, so hair may become drier, coarser, or thinner, including at the outer edges of the eyebrows. Other possibilities include skin inflammation, repeated plucking, nutritional problems, hormonal changes, alopecia areata, or medicines. The pattern, speed, and accompanying symptoms matter more than eyebrow appearance by itself.

An underactive thyroid may also present with fatigue, daytime sleepiness, constipation, feeling cold, cold hands and feet, or a hoarse voice. A clinician can examine the skin and hair and decide whether thyroid or other blood tests are useful.

Take a clear photo in similar lighting from time to time so gradual change is easier to describe. Avoid aggressive plucking, rubbing, harsh dyes, and unverified hair-growth products around the eyes. Mention recent illness, dietary restriction, new medicines, skin rash, or hair loss elsewhere at your appointment. Continue any prescribed thyroid medicine as directed rather than adjusting it for cosmetic changes.

Arrange a review when eyebrow thinning is new, progressing, patchy, or accompanied by scalp hair loss, rash, swelling, marked fatigue, or changes in weight or temperature tolerance. Seek prompt advice for painful, crusted, swollen, or infected-looking skin around the eyes. Sudden widespread hair loss warrants assessment because several treatable causes can look similar at first.

Does the pattern suggest a thyroid problem or a skin condition? Should my thyroid function or nutrient levels be checked? Could any medicine or cosmetic product be involved? When might regrowth be expected if a cause is treated?