Phases of hair growth
We have commented about this subject on other occasions. Your hair grows based on ts own life cycles or phases. There are three phases in the hair growth cycle that can occur at the same time in different areas of the head:
Anagen phase: this is the growth phase that lasts between 2 and 8 years and in this state is usually 90% of the hair.
Catagen phase: this is the transition phase in which the hair stops its growth over a period of 2 to 3 weeks. In this state is 1% of hair
Telogen phase: this is the resting phase that affects approximately 9% of hair and lasts 2 to 3 months.
An effluvium is a diffuse alopecia that occurs by "detachment" as a consequence of an exogenous or endogenous aggression on the hair follicles, which causes an alteration of the capillary cycle. Telogen effluvium occurs when many hair follicles that are in the anagen phase - growth - pass prematurely to the telogen phase - hair loss. From here comes his name.
It is simply the fact that we find a larger number of follicles in a state of rest than normal and may not affect all parts of the scalp equally, with the usual being that the hair becomes thinner on the top of head.
Seasonal telogen effluvium
We have reason to say that hair does fall in the spring. This is due to a seasonal telogen effluvium, which affects the majority of the population due to photoperiod, whereby light alters our hormones and, in turn, our hair.