Male pattern baldness begins with the recession of the hairline and results in complete hair loss across the top of the scalp. Female pattern baldness causes diffuse thinning behind the hairline but there is no recession of the hairline.

Alopecia is simply the medical term for hair loss. Causes of hair loss include disease, nutritional deficiency, hormone imbalance, and stress. However, by far the most common cause is what is called adrogenetic alopecia. Androgenetic refers to the fact that both a genetic predisposition to balding, and the influence of male hormones, play a part in this type of hair loss.

Genetics is not always simple, and it’s very hard to accurately predict who will go bald and how rapidly.

Androgenic Hormones

All normal men and women produce “male” hormones. The most common of these are testosterone and dihydrotestosterone (DHT). It is the exposure of the hair follicles to DHT, in a genetically susceptible person, over a period of time, which leads to androgenetic alopecia. Drugs like finasteride help in reducing levels of DHT.

There is alopecia areata, where discrete patches of scalp go bald; triangular alopecia, which tend to occur in a triangular pattern in the temporal area; alopecia universalis, in which the entire body may be affected; and various “toxic” alopecias, including those following a severe illness, sometimes with high fever, or following pregnancy. Toxic alopecias may also occur with low thyroid and / or pituitary gland function, or following chemotherapy. The cicatricial (scarring) alopecias occur following tissue destruction and inflammation.