Hair is made by an organ in your skin called a follicle. Within the human head, these follicles appear in natural sets of one to four, called follicular devices.
The development of head of hair is a cyclical process. The anagen period can last two to seven years. This is actually the growing period. The mane follicle produces "terminal" mane, or full healthy wild hair.
The telogen stage lasts about three months. This is actually the resting stage when the wild hair falls out. The hair is completed growing and it is released from the follicle, leaving the follicle clear. Then the anagen phase starts again.
Note: In humans, this will not happen all at one time. About 90 percent of the follicles are in the anagen phase and 10 % in the telogen stage at any moment.
When Hair Doesn't Grow since it Should Telogen effluvium is the increased shedding of some of the wild hair after it has came into the telogen period.
When certain situations arise -- like surgery, effects of medications, pregnancy etc. -- the growing routine is modified. Your body is saying, in effect, that it requires to place its energy into something apart from making mane. So a larger portion of head of hair production switches into the telogen period, so you see more shedding of wild hair than you usually would. This is usually reversible.
Anagen effluvium is the shedding of scalp that is in the anagen period. Since almost all of the scalp is in the anagen phase, this affects almost all the scalp. This occurs in chemotherapy, for example propecia online without doctor prescription.
In androgenetic hair thinning in females, the hair loss is usually diffuse, not patterned as it commonly occurs in men. Testosterone, the men hormone that is also present in small amounts in females, is changed into DHT by an enzyme called 5 alpha reductase. DHT causes certain follicles to decrease in size and also have a shortened anagen or development phase, lasting months rather than years.
Women have less hair thinning than men do, especially in leading, because they may have less 5 alpha reductase, which brings about less DHT, and they receive security by another enzyme called aromatase.