Like hair, the growth of hair that on he hands and feet is controlled by the hair follicle.The growth cycle of hair is divided into three periods：Anagen., Catagen and Telogen.
The duration of the anagen phase is different for different parts of the hair. The anagen phase of the hair on the head can last several years, while hair on he hands and feet lasts only a few weeks and beard lasts mostly a few months.
At the end of the anagen phase, the hair stops increasing in length and eventually falls off. Therefore, the final length of the hair depends on the duration of the anagen phase of the hair follicle and the growth rate of the hair during the anagen phase.
The duration of the anagen phase mostly depends on genes, however, other factors also take a part, such as hormones, age and other factors.
People's hair, beard and hair on he hands and feet or back, have their own growth characteristics. For example, beard and hair on the head grow faster and longer, while hair on he hands and feet grow slower and shorter. But there are also individual differences, therefore some people's hair on he hands and beard grow thin and short, while some people have thick, bushy hair.
In terms of the length of the beard, it grows to about 8cm on average. Some people's beards can grow to more than 1 meter and can even approach the ground, of course this is a very rare phenomenon.
