Baldness or Alopecia
Baldness, more formally known as alopecia, is the state of lacking hair where it usually would grow, especially on the head.
In balding, the hair follicle progressively shrinks. The hair that grows from it also shrinks, losing its pigmentation and decreasing the amount of time it spends in the Anagen or growth phase, which goes from lasting a normal 2-4 years to only a month or two, producing really fine " vellous " hair. The terminal stage in balding involves atrophy and fibrosis (scarring) of the hair follicle.
The most common form of baldness seen is pattern baldness, in which the hair recedes from the lateral sides of the forehead, known as 'receding brow' or 'receding hairline'. Additionally, a bald patch can develop on top (vertex).
The trigger for pattern baldness, which is also known as androgenic alopecia, is currently believed to be an enzyme, 5-alpha reductase, that converts the hormone testosterone into dihydrotestosterone (DHT), which inhibits hair growth. The age at which the enzyme appears, if it does at all, is genetically determined.
In balding, the hair follicle progressively shrinks. The hair that grows from it also shrinks, losing its pigmentation and decreasing the amount of time it spends in the Anagen or growth phase, which goes from lasting a normal 2-4 years to only a month or two, producing really fine " vellous " hair. The terminal stage in balding involves atrophy and fibrosis (scarring) of the hair follicle.
The most common form of baldness seen is pattern baldness, in which the hair recedes from the lateral sides of the forehead, known as 'receding brow' or 'receding hairline'. Additionally, a bald patch can develop on top (vertex).
The trigger for pattern baldness, which is also known as androgenic alopecia, is currently believed to be an enzyme, 5-alpha reductase, that converts the hormone testosterone into dihydrotestosterone (DHT), which inhibits hair growth. The age at which the enzyme appears, if it does at all, is genetically determined.