In 95% of patients with hair loss, their hair loss is inherited genetically. These hair loss genes make hair follicles sensitive to the hormone dihydrotestosterone or DHT. DHT slowly accumulates in the hair follicle and the follicle begins to shrink, choking out the hair.
This is first noticed as thinning hair, since the hair follicle begins producing only a very thin short hair. Eventually the hair follicle dies, no longer produces a hair and permanent baldness occurs. Baldness usually begins in men aged 20 to 30 and follows a progression of varying degrees, along the typical patterns of hair loss.
While some FDA approved medications such as Minoxidil/Rogaine or Propecia can slow the effects of male pattern baldness, they cannot reverse it. A Hair Transplant for Men is the only permanent solution to filling in the areas that you have lost hair.
Norwood Classification of Male Hair Loss: