How Does Human Hair Grow
When it comes to human hair growth, there are four phases, and they include:
- Anagen – The Growth Phase
- Catagen – The Transition Phase
- Telogen – The Resting Phase
- Exogen – The Shedding Phase
Human hair grows, on average, about half an inch each month. The anagen phase, or growth phase of the cycle, lasts from 2-7 years. Overall, the length of the anagen phase will determine the length of hair on a person.
Once the anagen phase nears its end, the transition stage known as the catagen phase begins. This phase is very short lived and only lasts around ten days. Despite its shortness, it is a very important part of the growth cycle since hair follicles decrease in size and detach from the dermal papilla.
Next, the telogen phase begins, this is better known as the resting phase of the hair growth cycle. This phase is 3-4 months long. In fact, anywhere from 10-15% of the hair on the scalp is in the telogen phase at any given moment. In other words, while the older hair is resting, the new hair is beginning to enter the growth phase.
The exogen phase of the hair growth cycle is better known as the shedding phase. This stage is when the old hair on the scalp detaches and sheds from the head. Anywhere from 50-150 hairs normally fall out of the scalp daily. As the exogen phase completes, a new bulb is forming, renewing the process with a return to the anagen phase.