Hair growth cycle
Each hair follicle goes through a constant cycle of growth, rest and finally shedding. This cycle continues over and over until something else happens to prevent the follicle from forming new hair. Understanding the hair growth cycle will help you identify problems that you may encounter with your hair.
Genetics determine hair follicles’ pattern of growth and rest. As we age, hair follicles are programmed to stop producing hair and spend more time in the resting stage.
The hair cycle is also affected by other external and environmental factors, such as lack of sleep, or stress. Leading a healthy lifestyle and trying to keep stress levels to a minimum are sure-fire ways to speed up the rate at which hair grows. Physical activity also encourages your body circulation including your scalp, promoting hair growth.
What are the stages of the hair growth cycle?
There are 3 stages of hair growth in the cycle, from actively beginning growth from the root to hair shedding:
1. Anagen, or growing stage
- The anagen stage is the growing period of a hair follicle
- This stage typically lasts about 3 to 5 years
- The anagen phase constitutes about 90% (1000 days or more) of the growth cycle
2. Catagen, or intermediate stage
- The catagen stage is the intermediate period of hair growth
- Hair follicles prepare themselves for the resting phase
- It lasts around 1-2 weeks
- During this phase, the deeper portions of the hair follicles start to collapse
3. Telogen, also known as the resting or shedding stage
- The telogen stage is the resting and shedding period of the hair cycle
- It usually lasts 3 to 4 months
At the end of this period, older hairs that have finished their life will fall out and newer hairs will begin to grow.