Research has found that male pattern baldness is associated with male sex hormones called androgens. The natural ageing process causes the growth cycle of hair to begin to weaken and the hair follicles shrink, producing shorter and finer strands of hair. Eventually, the growth cycle for each hair ends and no new hair grows in its place. Studies show that 30% of Caucasian (white) males start showing signs of male pattern baldness in their 30s, and 50% will experience male pattern baldness in their 50s. However, male pattern baldness is less common among Asian and African American men. Some reasons for thinning hair include:
Male pattern balding is an inherited condition from either side of the family. It is caused by a genetically determined sensitivity to the effects of dihydrotestosterone (DHT) in some areas of the scalp - this will shorten the growth/ anagen phase of the hair cycle.
Illness and medications
Some medications may disrupt your hair’s growth cycle, this could cause it to shed before it reaches its full length. Other medications may increase your production of hormones that cause male pattern baldness, such as DHT.