Definition of Male pattern baldness:

Male pattern baldness is the most common type of hair loss in men.

Causes, incidence, and risk factors:

Male pattern baldness is related to your genes and male sex hormones. It usually follows a pattern of receding hairline and hair thinning on the crown, and is caused by hormones and genetic predisposition.

Each strand of hair you have sits in a tiny hole (cavity) in the skin called a follicle. Baldness in general occurs when the hair follicle shrinks over time, resulting in shorter and finer hair. Eventually, the follicle does not grow a new hair. However, the follicles remain alive, which suggest that it's possible to grow new hair.