Our hair growth is a cycle that depends on the season, your age, and your type of hair. We have about 150,000 hairs on our scalps - about the same for men and women - and our hair grows about 0.3 to 0.5 mm per day or 1 cm per month (or 12 cm/5 inches per year). We lose between 40 to 180 hairs per day, with most people falling into the 40 to 80 range.
The anagen phase: The hair growth stage. This can be a cycle of 3 to 5 years, and up to 7 years or longer for some lucky people! This phase determines how long your hair will be - the longer the phase, the longer you can grow your hair. The definition of this phase is "when the follicle produces a hair".
If your hair has a 3 year cycle, your maximum length will be 36 cm or 15 inches. For a 5 year cycle, you might see up to 60 cm or 24 inches. For a 7 year cycle, you might see lengths of 84 cm or 35 inches!
The catagen phase: The hair moves from underneath our skin to the surface. Effectively, the hair strand is squeezed upwards and rests near the opening of the sebaceous duct. It will stay there until it sheds.
The telogen phase: The hair rests for two to four months with no growth, then it is shed. The follicle then enters the anagen phase and the process starts again!
These three stages are independent in each hair follicle. You generally have about 85% of your hair in the anagen (growing) phase, about 12% in telogen (shedding) phase, and 1% in the catagen (squeezing and resting) phase. You might find a number of follicles in one phase all at once during the initial growth of hair (after hair removal or pregnancy) or during re-growth (after chemotherapy).
As a note, hair does not grow back thicker or faster when you remove it! It only seems to come back faster because we are paying attention to it and, if it's a large area, because it feels spiky.
I know some of us started off life as straight haired girls and went curly at some point naturally. What happened there?
Join me in the next post to explore this question!