Hair loss is more frequent in men, though women may also be concerned. It affects approximately 15% of 20-year-old men, 30% of 30-year-old men and one in two 50-year-old men, versus 30% of 50-year-old women.
We lose on average 50 to 100 hairs per day. Hair that falls out can be replaced by new growth:
- The anagen phase is the hair growth phase, it lasts on average 3 years (the duration may vary with gender and from one individual to the next). This is the longest part of the hair growth cycle.
- The catagen, or regression phase, lasting 3 weeks on average, during which the hair stops growing.
- The telogen, or hair loss phase, lasting 3 months on average: the hair falls naturally due to friction, brushing and pressure from a new root forming in the scalp. A new hair growth cycle can then start with a new hair.
This is the normal life cycle of a hair.