Hair Loss In Male Pattern Baldness

Written by Admin on November 16th, 2010

male pattern baldness or otherwise known as androgenetic aloprecia affects millions of men around the world. Andro refers to the androgens (testosterone, dihydrotestosterone) necessary to produce male pattern hair loss. Genetic refers to the inherited gene necessary for male pattern baldness to occur. Hair loss may begin any time after puberty when blood levels of androgens rise; it usually begins receding in the temporal areas. In general, those who begin losing hair in their 20s will have the most severe hair loss outcomes.


Hamilton and Norwood have classified male pattern baldness shown on the picture below. Hamilton found that androgens are necessary for the development of male pattern baldness. Androgens present do not need to be greater than normal for baldness to occur. In every male hair loss will occur to some degree, however, if the gene for hair loss is present, male pattern baldness will take place.


testosterone is responsible for the growth of under arm and pubic hair, while Dihydrotestosterone (DHT) is responsible for beard growth and male pattern hair loss. DHT is the conversion of testosterone by the enzyme 5 – reductase. DHT works by binding, then entering into the cell to interact with the nucleus, changing the DNA and ultimately causing the hair follicle growth to cease. Finasteride (Propecia) works by blocking the enzyme, decreasing the amount of DHT produced therefore slowing down or stopping the process of hair loss.


There are 3 phases in the hair growth cycle; Anagen – growth phase, Catagen degradation phase, and Telogen resting phase. Hair growth cycle is affected when there is a lower percentage of hair in anagen phase than the percentage of hair in telogen phase. Hairs in telogen phase are much more subject to loss with daily trauma such as combing and washing. In male pattern baldness, hair shafts become gradually miniaturized, meaning over time, the hair shaft slowly becomes smaller in diameter and length. Pigment (colour) production is also terminated with miniaturization causing the fine hair to become lighter in colour and affected area to appear thin. Over time, those hair follicles will be permanently terminated.


In short, male pattern hair loss is an inherited condition which can be passed down from either the father or mother. The rate and severity of hair loss is unpredictable, although the severity increases with age. If the condition is present it will be progressive and relentless. Hair loss is most likely to occur between late teen-age years and age 40-50 years.