Normal at the person about 100 hair daily drop out, increase in this quantity can demonstrate pathological processes in an organism. The patient notices that a large number of hair remains on a hairbrush, on bed linen, a towel, in plum of the bathroom and on use objects.

About 0.1% of all population of the planet at least once observed at themselves the raised hair loss.

Density of indumentum differs at different people and on different body parts. It depends on age, sex, race, etc. The total number of hair on the head of blondes makes 140 thousand, brown-haired persons have 109 thousand, brunettes have 102 thousand, at red – 88 thousand.

All hair do not grow at the same time, and there pass 3 main growth phases: anagen, katagen and telogen. Anagen name a phase of active growth of hair – its duration is from 2 to 5 years. During the day the hair is extended on average on 0.1-0.4 mm, and at women hair grow quicker, than at men. In a phase of a katagen there is growth delay, and it lasts from 4 to 6 weeks. During a phase of a telogen growth of hair stops, their life cycle comes to the end and they drop out. This period proceeds 2–3 months and conditions to start a new phase of an anagen are during this time created.