Under a healthy hair growth cycle, 90% of hair is in Anagen (Growth) phase and 10% is in Catagen (Resting) and Telogen (Falling) phase. Hair loss starts when this growth cycle is disturbed and more than 100 strands per day are lost. In such a situation, less hair is in growth phase and more is in resting and falling phase.
During this phase, a hair grows about one centimeter, or about half of an inch, every 28 days. Scalp hair stays in this active phase of growth for two to six years. At any time, about 80% to 90% of the hairs on your head are in the anagen phase.
The amount of time that a hair follicle stays in the anagen phase is genetically determined. Some people naturally have longer anagen phases and can grow their hair very long, while others will never see their hair get much longer than a foot and a half. At the end of the anagen phase, an unknown signal causes the follicle to go into the catagen phase.
he catagen phase is the second part of a hair’s lifecycle. It comes after the anagen phase of hair growth, but before the final telogen phase. During the anagen phase, a hair bulb forms at the bottom of the hair follicle and matures into a full-length strand of hair that grows outwards past the scalp barrier. During the catagen phase, however, structural changes take place in the maturing hair over a number of weeks.
A resting phase when your hair is released and falls out. The follicle then remains inactive for 3 months and the whole process is repeated. Each hair follicle is independent and goes through the growth cycle at different times, otherwise all your hair would fall out at once. Instead, you only shed a certain number of hairs a day – up to 80 hairs on a healthy head of hair.
But the most common cause for hair loss in men is MALE PATTERN BALDNESS (MPB) OR ANDROGENETIC ALOPECIA. Male Pattern Baldness is a genetic condition caused by a by-product of testosterone named Dihydrotestosterone, or DHT. DHT attaches to the hair follicles and causes them to shrink over time, which causes the hair to become thinner and thinner until some men become totally bald on the top of the head.
Hair loss in men, especially Androgenetic Alopecia, is an external problem and should be dealt with only externally.
Androgentic Alopecia or Male Pattern Baldness is an internal issue and not just external.