hair (control of growth)
Last reviewed 01/2018
Hair growth is dependent factors as diverse as hormones, principally sex hormones, and nutrition.
The hair in Man goes through 3 phases:
- anagen: hair grows over a period of weeks to years
- catagen: growth stops over a period of days
- telogen: no growth and ultimately shedding of hair with production of new hair in folliclular bud at site
In Man, the three stages are asynchronous between hairs. However, disease states e.g. telogen effluvium, and drugs such as cytotoxics are common causes of synchronization of growth stages resulting in alopecia.