If you are struggling to understand what the words anagen, catagen, and telogen mean, don’t pull your hair out. The hair on your scalp grows around 0.3 to 0.4 mm per day or roughly 6 inches per year and unlike other mammals, the growth of human hair is random instead of seasonal. Anagen, catagen, and telogen are the three stages of hair growth and shedding that occurs at any point of time, possibly even right now as you are reading this!
Anagen
The active phase of hair growth, also known as anagen, happens when the cells in the roots of your hair are dividing quickly. Hair that has stopped growing or no longer in the anagen phase is pushed out and hew hair is formed. During the anagen phase, your hair grows about 1 cm every 28 days and your scalp hair stays in this active phase for two to six years.
If you have relatively short hair, it is because your anagen phase is shorter as compared to people with very long hair. Have you ever thought about why the hair on your arms, legs, eyebrows, and eyelashes are so much shorter than the hair on your scalp? That is because those parts of your body have a much shorter anagen phase!
Catagen
The catagen phase of hair growth is the transitional period and approximately 3% of all the hair on your body are in this phase at any one point of time. This transitional phase lasts for about two to three weeks where hair growth stops and the outer root sheath of your hair shrinks and attaches its root. This creates what is known as a club hair.
Telogen
Finally, telogen is the phase of which your hair takes a break from growing and this usually accounts for 6 – 8% of all the hair on your body and about 25 to 100 telogen hairs are shed normally each day.The telogen phase lasts for roughly 100 days for the hair on your scalp and slightly longer for the hairs on your eyelash, eyebrow, arm, and leg. While this phase is in progress, your hair follicles are totally at rest and the club hair forms to completion. If you have ever pulled out your hair only to see a solid, dry, and white material at the root, that is because your hair was in the telogen phase!
It is important to note that the time taken from the anagen to telogen phase is dependent upon two different factors, namely the area of the body, and the genetic makeup which includes the hormonal factors of each person. Therefore, it is important to understand the rate of hair growth on different parts of the body.