Final answer:
Androgenic alopecia is characterized by progressive hair thinning and loss, a receding hairline in men, and a widening part or thinning hair on the top of the scalp in women. It is caused by the effects of androgens, male sex hormones, on the hair follicles.
Step-by-step explanation:
Androgenic alopecia, also known as male pattern baldness, is a common form of hair loss that occurs in both men and women. It is characterized by a gradual thinning of the hair on the scalp, which typically starts at the hairline and crown of the head. The features of androgenic alopecia include:
- Progressive hair thinning and loss
- A receding hairline in men
- A widening part or thinning hair on the top of the scalp in women
These features are caused by the effects of androgens, a type of male sex hormone, on the hair follicles. Androgens can shrink the hair follicles, leading to shorter and thinner hair strands. They can also prolong the resting phase of the hair growth cycle, leading to reduced hair growth and increased hair loss.