Male Pattern Hair Loss 

In Males, genetic hair loss is inherited from either parent and usually begins in the late teens or early twenties.  It is characterized by a gradual thinning of hair at the temples and/or top of the scalp.  This may eventually lead to total baldness on top of the scalp.

Norwood classified the male pattern of baldness based on 7 stages.

The prevalence of Norwood Stage 3 or greater pattern of hair loss increases with age :-

Typical Males Pattern Baldness progress

Age                         Percentages of Hair Loss
18 to 29                              12% to 16%
40 to 49                            45% to 60%
Above 70                                  80%