Male pattern hair loss is the most common type of hair loss. It is a genetic condition, which results from the increased sensitivity to androgens (male sex hormones) in certain parts of the human scalp. In the past, baldness was perceived as an unfortunate or undesirable thing. Fortunately, this approach has shifted with time and today a clean-shaven head is usually seen as symbol of style, power and masculinity.

Some men have certain areas in the skin on their head that are highly sensitive to the levels male sex hormones in their blood. The hormones cause the hair follicles to shrink. At some point they become too small to keep up with the regeneration rate of hair. The follicles are still active only that they are unable to perform their task.

Hair loss in men usually starts at ages 20 to 30 and then follows a common pattern. The hairline and crown areas an the scalp start losing hair until these two zones emerge into a single bald spot with the typical U-shape formed by the remaining hair on the sides and the back of the head. The hair in these areas is usually finer and shows lower growth rates than earlier.