Hereditary-pattern baldness starts with thinning of the hair and often progresses to complete hair loss on parts of the scalp. Hairs on the pillow, in the tub or on the comb are unreliable symptoms of hair loss. The average non-balding person loses 100 hairs per day, and more hair may fall out under certain circumstances, such as after childbirth or a serious illness.
In men, hair loss typically begins at the temples and crown and proceeds in an M-shaped pattern. In the most advanced stage, only a rim of hair along the side and back of the scalp remains.
In women, hair loss tends to be more widespread but better hidden. The top of the head down the middle is most commonly affected, often in a "Christmas tree" pattern. In contrast to men, the hairline along the forehead and temples usually remains normal in women. Complete loss of hair in any one place on the scalp is unusual and may suggest that a different problem is the cause, such as alopecia areata (an immune system disorder that causes bald patches), a fungus infection or one of a number of other skin conditions.