Hypothyroidism and eyebrows: what to know

Hair growth can slow when thyroid hormone activity is low. Some people notice dry or coarse hair, scalp hair thinning and reduced fullness near the outer ends of the eyebrows. This finding is not specific to hypothyroidism: skin conditions, inflammation, nutritional problems, repeated plucking and some medicines can also alter eyebrow growth.

Look for accompanying changes such as fatigue, feeling unusually cold, constipation, daytime sleepiness, a hoarse voice or cold hands and feet. Patchy loss, redness, scaling, pain or loss of eyelashes may suggest a local skin or immune-related problem rather than a thyroid explanation.

Arrange a routine medical review if eyebrow thinning is new, progressive or accompanied by other symptoms of thyroid imbalance. Do not start thyroid medicine or high-dose supplements based on eyebrow changes alone. Avoid frequent plucking, harsh cosmetics and irritating skin products while the cause is being assessed. Bring photographs showing when the change began and a list of medicines, supplements and recent illnesses.

Seek prompt care for rapidly spreading hair loss, painful or inflamed skin, sores, marked swelling around the eyes or changes in vision. Make a routine appointment for persistent thinning, especially when it occurs with fatigue, cold intolerance, constipation or general weakness. A clinician can examine the skin and hair pattern and decide whether thyroid or other tests are appropriate.

Ask whether your symptoms warrant thyroid testing, whether a skin or hair condition could be involved, and whether any medicine or supplement may be contributing. Mention hair loss elsewhere, itching or scaling, menstrual changes, dietary restrictions and any family history of thyroid or autoimmune illness.