I've lost the outer third of my eyebrows. what could be causing this? i'm a 52 yr. old female---post menopausal.

Possibly thyroid : Eye brow loss is definitely a cosmetic concern. Many causes are associated with brow loss. The outer 1/3 loss may be associated with hypothyroidism. Numerous other causes including primary dermatoses, autoimmune conditions, infections, neoplasms, trauma, exogenous agents, and genetic diseases need a systemic review, typically by a dermatologist.