Growth Cycle of Hair, How hair Grows?

Hair passes through a growth cycle broken up into three main phases: an active growth phase known as the anagen phase; a short, transitional catagen phase during which the hair stops growing and the hair bulb begins to break down (but there is still cellular activity in the papilla); and a resting telogen phase when no growth takes place and the hair is ready to be shed. The duration of the different phases varies from person to person, but the anagen phase can last anything from three to seven years, and in some cases even up to nine years. The catagen phase lasts roughly two to four weeks, while the telogen phase is estimated to last three to four months.

The anagen phase: Active growth takes place in the hair bulb. This phase can last for years, often between three and seven years.

The catagen phase: This is a relatively short phase, during which the follicle stops producing hair and the hair bulb starts to break down.

The telogen phase: A resting phase during which there is no growth and the hair is ready to be shed.

A new anagen phase: The old 'club hair' is ready to fall or be pushed out.