• hair_science

Male Pattern Hair Loss

The most common cause of hair loss in men is due to the hair follicle’s sensitivity to the hormone Dihydrotestosterone, or DHT. DHT sensitive hair follicles are generally found on the top front section of the head. These hairs become weaker, finer, and eventually stop growing, which causes balding. DHT may never affect the hair around the sides of the head even though these hairs are exposed to DHT, because hair follicles on the side of the head may not be sensitive to the hormone.

A scale popularly used to measure baldness in men is the Hamilton-Norwood scale. This scale measures the 7 stages of baldness in men, which are described below:

Male Baldness: The Norwood Scale 


Class I represents a normal head of hair with no visible hair loss.

Class II is characterized by the beginning of a receding hairline, which causes a “widow’s peak” on the forehead.  Donor hair may be considered.

Class III patients exhibit a more significant decline in hair above the temples as well as receding from the forehead. Hair loss is starting to become significant on the crown. 

Class IV hair loss may become more noticeable on the crown, or patients may have significant hair loss above the temples and/or front anterior areas. 

Class V hair loss approaches significant levels with most hair loss occurring on the top of the vertex and crown. Hair transplantation for this Class and higher Class levels may require more grafts to provide coverage and density.

Class VI patients show major hair loss, but still have areas with donor hair available. Transplanting this hair can still have excellent results.

Class VII patients show the most significant loss of hair. There may still be sufficient donor hair for transplantation; however, results may be limited.