The primary cause of hair loss in men is genetics. In fact, 95% of all noticeable hair loss is caused by androgenic alopecia — also known as male pattern baldness — which is triggered by the hormones dihydrotestosterone and testosterone. (Androgenic alopecia also the most common form of hair loss for women, and for everyone, the odds of hair loss increase the older you get.)

When you have androgenic alopecia, the hair growth cycle is affected and the hair shafts become progressively miniaturized. For some men, over time, the involved areas can completely lose all follicles and you’ll go completely bald.

The characteristic signs of androgenic alopecia are hair receding from the lateral sides of the forehead (also called a “receding hairline”) or a thinning crown with balding to the area known as the “vertex.” Both can become more pronounced until they eventually meet, leaving a horseshoe-shaped ring of hair around the back of the head. The progression of male pattern baldness is generally classified on the Hamilton–Norwood scale, which ranges from stages I to VII.

If you experience male pattern baldness, remember that you’re not alone! Studies show that 30% of men over 30 and 50% of men over 50 experience signs of hair loss.