The development of male pattern hair loss goes through typical sequences. Hair loss initially leads to gradual thinning, at the same time frontal and temporal hairline starts receding and finally develops into frontal baldness, later involving the mid scalp and crown area.
Male pattern Hair loss is classified in to 7 Types.
In Type I, there is minimum recession along the anterior border of hairline.
In Type II, there is symmetrical triangular area of recession on both side of frontal hairline . If a vertical line is drawn in front of the ear and a second vertical line is drawn 2 cm in front of first. The triangular recession stop in front of the second vertical line.
In Type III, there is still symmetrical triangular area of recession on both side of the frontal hairline . This symmetrical triangular area of recession on both side of the frontal hair line extend up to the vertical line in front of the ear.
In Type IV, The frontal hair line get receded and become extremely thin, the triangular area of recession extend beyond the vertical line in front of the ear . At the same time there is established hair loss in the crown area. The crown baldness is still clearly separated from the frontal baldness by a band of hair.
In Type V, the frontal hairline is completely lost . The frontal baldness and crown baldness is still separated from each other by a thin band of hair.
In Type VI, the bridge between frontal and crown baldness is lost . The entire area of baldness is greater laterally and posteriorly than the Type 5 hair loss.
In Type VII, the baldness become most severe. All that remain is band of thin hair in the occipital, parietal and temporal area.