Baldness is determined by multiple genetic factors. It cannot be categorically stated that baldness follows the mother's line or anyone else's, or that it skips generations. Both men and women lose hair density as they age. Men develop a typical pattern of baldness, associated with the presence of the male hormone testosterone. The use of steroids during adolescence and young adulthood may accelerate the effects of testosterone on baldness.
Women also develop a characteristic pattern of hair loss.
Usually baldness is not caused by a disease but is genetic and permanent. On average, about 100 hairs are lost from the head every day. Each individual hair survives for an average of 4.5 years, during which time it grows about half an inch a month. Usually in its 5th year, the hair falls out and is replaced within 6 months by a new one. Genetic baldness is caused by the body's failure to produce new hairs and not by excessive hair loss.