Hair Loss for Women
Hair Loss for Men
- 25% of men who experience male pattern baldness begin the process by age 21
- By the age of 35, 2/3 of all men experience significantly thinning hair
- Male pattern baldness is inherited
Androgenic alopecia, or male pattern baldness (MPB), is the most common cause for hair loss in men. Although MPB is usually thought of as a problem for older men, 25% of men who experience MPB begin the process by the age of 21 and by the age of 35, two-thirds of all men will be experiencing significantly thinning hair. While some men attribute their hair loss to wearing hats, the pillow they sleep on or “something” in the water, MPB is actually a hereditary condition whereby follicles in the thinning area are susceptible to the hormone dihydrotestosterone or DHT.
In men, testosterone gets converted to DHT by the enzyme 5-alpha reductase. Once formed, the DHT can bind to receptors on certain hair follicles. The follicles that have receptors for DHT are those in the area where thinning is noted. Since the follicles on the sides and back of the head usually lack these receptors, the hair found here remains healthy. The number of follicles with DHT receptors, along with their locations, is genetically determined, which results in greater hair loss for some men and less for others. By binding to these receptors, DHT results in shortening the lifespan for the affected follicles. The once robust hair becomes finer and finer as the follicle prematurely ages until it finally stops growing hair all together. The medication finasteride (Propecia) works by irreversibly binding to the enzyme 5-alpha reductase and significantly decreasing the production of DHT. With less DHT in the system, there’s less of it to bind to the follicles, resulting in diminished hair loss.
Although androgenic alopecia is by far the most common reason for hair loss in men, responsible for 95% of hair loss cases, there are other factors that contribute to thinning hair. Medications, stress, hypothyroidism, iron deficiency, scarring alopecia, and alopecia areata are a few other causes that may result in thinning hair. As the name indicates, MPB occurs in predictable patterns and can usually be diagnosed based on the appearance and pattern of hair loss along with a detailed medical history: no further testing is usually required. If another reason for hair loss is suspected, blood tests or a skin biopsy may aid in determining the diagnosis.