Impact of Thyroid Dysfunction on Hair Disorders

Thyroid hormones (THs) significantly impact hair disorders, with conditions like hyperthyroidism and hypothyroidism associated with widespread hair shedding. Approximately 50% of individuals with hyperthyroidism and 33% with hypothyroidism experience hair loss. THs directly affect hair follicles, influencing hair biology variables and regulating the hair growth cycle. Thyrotoxicosis can cause fine, silky hair and possibly diffuse non-scarring alopecia, while hypothyroidism can lead to slow-growing, coarse, dry, brittle hair, and possibly alopecia. Alopecia patients have an 8-28% prevalence of thyroid disease. The relationship between thyroid disorders and Female Pattern Hair Loss (FPHL) is not fully understood, but hypothyroidism was observed in 31.25% of FPHL patients in one study. The study concludes that understanding how THs govern skin biology could lead to the use of TH agonists or inhibitors to treat various skin and hair problems.