Loss of eyebrow hair can be distressing due to the cosmetic importance of eyebrows, and is a relatively common concern. Thinning may appear on one eyebrow or both, in patches or uniformly.
Causes of Thinning Eyebrows
The primary cause of thinning brows is due to aging. As women age the hormone estrogen becomes depleted. Dihydrotestosterone, an estrogen found in hair follicles that plays an important roll in the hair growth cycle, also becomes depleted and shortens the hair cycle growth pattern resulting in thinner brow hair. Certain types of chemotherapy, diseases, medications and family genetics can also cause the loss of brow hair.