If the hair loss is caused by alopecia, men will lose their hair extensively. Hair loss is sometimes associated with other health issues such as coronary heart disease and enlargement of the prostate, as well as disorders of insulin resistance like diabetes and obesity and high blood pressure. Men usually notice hair loss after puberty, because that's the time when serum androgen levels raise above the low level. Most men have some type of baldness by the time they are in their 60s, but the age when the hair loss starts is variable.
It is good to find out as much as you can about the hair cycle and the possible hair loss causes, since it will be easier for you to fight it. Hair cycle lasts three years approximately. When affected with some kind of imbalance, the size of hair follicles changes, so the thin stump of hair stops growing out to the skin surface. The follicles in the temporal, frontal and vertex area of the scalp get shorter in the Anagen phase, followed by miniaturization of the hair follicles. It affects the percentage of hairs in Anagen phase and the duration of Anagen diminishes in areas affected by Androgenetic alopecia which results in shorter hairs. People affected with classic pattern baldness loose hair in a well-defined pattern, with hair loss beginning above both temples and thinning of the hair at the crown of the head. It is also known by the term "Hippocratic balding" and it may sometimes progress to complete baldness.
Male baldness is known also as androgenic alopecia, since inherited sensitivity to the effects of androgens (male hormones) on scalp hair follicles causes them to shrink and prevents them from producing hair normally. After puberty, hair follicles in the center of the scalp and over the temple of the individuals that get affected with this condition begin to miniaturize, producing small, fine hairs which are difficult to see. Hair follicles over the ears and around the posterior of the scalp do not possess this enzyme so some portion of normal hair is maintained.
Male pattern baldness is a hereditary form of hair loss. Factors that cause hair loss besides genetics are side effects from medications, hormones, stress and diseases. The good news is that it can often be reversed in a relatively short period of time. It is also important that you speak with a doctor if you happen to notice a significant amount of hair shedding. Your doctor can run all of the necessary tests to figure out if there is a serious medical condition that could be contributing to your hair loss.