Hair growth can be conditioned by multiple factors, which can be genetic, nutritional, psychological and even hormonal. Similarly, the correct circulation of blood flow through the scalp is going to be another important factor that will determine the growth rate of our hair.
Studies have shown that hair can grow from one centimeter to one and a half centimeters per month, and 15 centimeters per year. This growth is more noticeable in women than in men, and with age, the rate of growth usually decreases. The predominant factor in hair loss is undoubtedly genetics.
Stages of hair growth
The growth cycle of human hair is divided into 3 main phases:
- Anagen: It is the stage of growth and the longest, lasting between 2 and 6 years.
- Catagen: It is a transition stage between the first and the last stage.
- Telogen: It is the resting phase, and remains until the hair detaches to start a new cycle.
These cycles mentioned above do not occur in a homogeneous way, since in the entire scalp there will always be a percentage of hairs that are in one phase or another. In the absence of conditions, it is normal that 85% of the hair is in the anagen phase, 14% in the catagen phase and 1% in the telogen phase.
As is well known, there are some conditions that cause the hair to go from being mostly from the anagen phase to the resting phase, which in the long term results in hair loss and it is difficult for hair to recover. Among these conditions we can highlight thyroid diseases, hypozinchemia, postpartum and iron deficiency.