Hair loss that is the result of hormonal changes that convert terminal hair to vellus hair is called

• A. Alopecia areata
• B. Telogen effluvium
• C. Androgenic alopecia
• D. Traction alopecia

Answer: (C)

Hormones, especially androgens, influence hair growth by causing follicles to shrink and produce finer hair. Terminal hair is thick and pigmented, while vellus hair is fine and lightly colored. In androgenic alopecia, follicles that are sensitive to androgens undergo miniaturization over time, so their terminal hairs convert to vellus-type hairs and the scalp shows progressive thinning. This pattern—hormone-driven shrinking of follicles leading to finer, lighter hair—is the hallmark of androgenic alopecia.

Other options describe different mechanisms: alopecia areata is autoimmune patchy loss, telogen effluvium is diffuse shedding from a disruption of the hair growth cycle, and traction alopecia results from mechanical pulling on the hair.