So if you enjoyed the last hair related post I did (HERE) I’ve got another one to share with you this week! Did you know that a single strand of human hair goes through 3 stages? There are primarily 3 stages of growth and shedding for human hair and interestingly, at any given time, the hairs on our head will be at different stages of this cycle.
First off lets take a quick look at the structure of the human hair.
(Image Source: Wikkimedia Commons)
We can divide the structure of a hair strand into 2 parts; the shaft and the root. The structure of the shaft was explained in detail in the past post on hair which I have linked to in the beginning of this post. The focus today will be on the root since it is this region that plays an important role in the hair growth cycle! The hair follicle/ root end in a bulb like structure which is where cell division occurs to produce new hair strands. Like I mentioned earlier the human hair growth cycle can be divided into 3 stages.
1. Anagen stage
This is also refered to as the active phase of the hair cycle. This is because during this stage, the hair is actively growing with materials being deposited on the hair shaft by the cells in the follicle. Cells above and around the hair papilla actively divide and grow upwards during this phase to form the hair shaft. During this phase, hair can grow at a rate of 1cm every 28 days. Hair on the scalp can be in the anagen phase anywhere between 2 to 6 years and the exact time frame is found to be genetically determined. The hair on other parts of the human body have a much shorter anagen phase which is why body hair, lashes etc are much shorter than hair on the scalp.
2. Catagen stage
This is refered to as the transition phase. At any given time 3% of scalp hair is in this phase. During this phase, protein and pigmentaion production stops.The outer areas of the root start to shrink and attach themselves to the main root and the resulting hair is called club hair. This Phase is thought to last for 2 to 3 weeks.
3. Telogen Stage
This stage lasts for almost 100 days in the case of human scalp hair. During this phase the club hair is fully formed. you must have heard at some point how its normal to shed 100 hair strands a day. Well, the strands that are shed are usually in the telogen phase 🙂 This is also aided by the pushing out of old hair by the newly developing hair in the follicle.
These 3 stages of hair growth and renewal are greatly affected by external factors like diet, environment and chemical exposure. So in addition to thanking good genetics, it is very important to have a healthy diet and lifestyle as well to have thick growing hair!
I hope this post helped you guys understand your hair a little bit better!
Until next time ..ciao!!