Your hair continuously goes through a process of renewal and shedding, this cyclical process is known as the hair growth cycle. Interestingly, both hair growth and hair loss are a part of the natural hair cycle.
Did you know? Our hair grows between 0.5 and 1.7 cm per month. Also, losing about 50 to 100 hair strands per day (in exogen phase) is natural and normal.
Understanding the Hair Growth Phases
As the hair cycle passes through the four stages of hair growth, it determines the growth, shedding, and renewal of hair follicles. The hair cycle comprises four hair cycle phases – Anagen, Catagen, Telogen, and Exogen. To take a proactive stance against hair concerns and premature hair loss, it is crucial to understand the stages of hair cycle.
1. Anagen Phase
Also referred to as the growth phase, it is the active growth phase of the hair cycle. During this stage, hair follicles actively produce new hair cells, which push older cells upward and eventually form the visible hair shaft. It’s the duration of the anagen phase that decides hair quality and health. The length of the stage varies from person to person and is influenced by genetics, hormones, and other factors. Studies show that on average, the anagen phase lasts about 3 years for scalp hair, it may go up to 5 years.
2. Catagen Phase
The catagen or the transition phase comes immediately after the anagen phase. During this phase, the hair follicles begin to shrink and detach from the dermal papilla, a structure that supplies nutrients to the hair. This is a transition phase and lasts for 2-3 weeks and marks the end of active hair growth. Approximately 3% to 5% of all hairs are in this stage at any time.
3. Telogen Phase
In the telogen phase of the hair cycle, the hair follicles tend to become inactive. The old hair remains in place, meaning hair doesn’t fall during this phase. Studies reveal that almost 10%-15% of the total hair stands enter the telogen phase which lasts for about 3 months.
New hairs may start forming in the follicle which had shed the hair in the previous phase.
4. Exogen Phase
The exogen phase marks the end of the old hair and makes way for new hair growth. As the hair follicle enters the exogen phase, it pushes out the hair that was in the telogen phase by the new hair growing underneath it. Shedding is influenced by various factors, including stress, hormonal changes, and certain medical conditions. After the exogen phase, the cycle returns to the anagen phase, and the process starts anew with the growth of a new hair shaft.
Each phase lasts for a different length of time. Not all hair follicles are in the same stage at the same time. Each hair follicle operates independently, which is why one experiences an active mix of growing, resting, and shedding on the scalp at any given time. Understanding these phases is important for managing hair health. Remember, the hair growth cycle time is different for different people, and normal hair loss is natural. But if you are experiencing hair loss at a faster rate, it is best to see a doctor.