Androgenic alopecia causes progressive hair thinning due to hormonal changes and genetic predisposition, typically starting after age 30. The condition affects both men and women, though patterns differ.
Androgenic alopecia, also called androgenetic alopecia, develops when hair follicles shrink due to sensitivity to dihydrotestosterone (DHT), a derivative of testosterone. Over time, affected follicles produce finer, shorter hairs until they stop growing entirely.
The process begins with a gradual recession of the hairline in men and diffuse thinning over the crown in women. Without intervention, hair loss continues until only fine, colorless vellus hairs remain.
Androgenic alopecia manifests differently in men and women:
| Gender | Pattern | Typical Onset |
|---|---|---|
| Men | Receding hairline forming an "M" shape, eventual bald spot on crown | After age 30 |
| Women | Diffuse thinning over entire scalp, especially crown | After age 50 |
Men develop noticeable hair loss earlier than women, often beginning in their late 20s or early 30s. Women typically see symptoms after menopause, between ages 50 and 60.
Androgenic alopecia requires both genetic susceptibility and hormonal triggers. The AR gene, which regulates DHT sensitivity, plays a key role. A 2017 study identified over 280 genetic markers linked to male pattern baldness.
DHT binds to receptors in hair follicles, shortening the growth phase (anagen) and lengthening the resting phase (telogen). This imbalance causes follicles to produce weaker hairs over time.
Many people confuse androgenic alopecia with other forms of hair loss, such as alopecia areata (patchy, autoimmune-related hair loss) or telogen effluvium (temporary shedding due to stress or illness). Unlike these conditions, androgenic alopecia progresses slowly and predictably.
Another myth is that excessive hat-wearing or poor circulation causes androgenic alopecia. While these factors may contribute to other hair loss types, they don't trigger androgenetic patterns.
Doctors diagnose androgenic alopecia through visual examination, medical history, and sometimes blood tests. Treatments include:
Early intervention yields the best results. For example, a 2016 study found that men using finasteride for five years maintained or regrew hair in 48% of cases.
I've seen firsthand how effective minoxidil can be for women with diffuse thinning. A patient of mine regained noticeable density after six months of consistent use.
While genetics determine susceptibility, certain factors may worsen androgenic alopecia:
Regular exercise, a balanced diet, and stress management may help slow progression. However, no lifestyle change can prevent androgenic alopecia in genetically predisposed individuals.