The Hair Growth Cycle
The hair growth cycle consists of four distinct stages: anagen, catagen, telogen and exogen.
The hair growth cycle consists of four distinct stages: anagen, catagen, telogen and exogen
Your hair grows around half an inch a month [about 6 inches a year], and faster in the summer than in winter. The growth phase, or anagen phase, lasts an average of 3-5 years — so a full-length hair averages 18 to 30 inches. The anagen phase is generally longer in people of Asian descent, and can last as much as 7 years — meaning your hair may be able to grow up to 3 feet long!
At the end of the anagen phase, your hair enters the catagen phase. This short transitional phase lasts approximately 10 days.
The telogen phase is a resting period of around 3 months, when strands remain in their follicles but are not actively growing.
Finally, strands are released from their follicles and fall out. Now the whole process can begin again!
Each hair follicle is independent and goes through the growth cycle at different times — otherwise all your hair would fall out at once! Instead, you only shed a certain number of hairs a day – 80 to 100 hairs on a healthy head of hair.
Hair loss, hair thinning and problems with hair growth may occur when your growth cycle is disrupted. This can be triggered by conditions such as metabolic imbalances, illness or improper nutrition.
For instance, around 12 weeks after restrictive dieting or a high fever, you may experience telogen effluvium (sudden diffuse hair fall). This occurs when your anagen (growth) phase is cut short, and many hairs enter the telogen (resting) phase at the same time – resulting in increased hair fall 3 months later during the exogen (shedding) phase.
If your hair growth cycle is constantly disrupted (for example, not supported with good nutrition, you may find that your hair will not grow as long as it used to. This is because your hairs are never allowed to stay in the anagen phase long enough to reach the desired length.
If you are worried about any hair or scalp issue, our Clinics in London and New York specialise in all aspects of hair and scalp health, and will be pleased to welcome you.