The Basics: Hair Growth Cycle

Now that we understand our hair components and structure we can move on to the next important thing. How our hair grows. There are a lot of myths around hair growth. Whether it does or does not grow, the role of genes, age , etc So let’s just keep it simple and try understand the growth cycle that is common to us all regardless of all the above.

The hair follicle grows in continuous cycles over the years and there are three distinct stages in the cycle:

  1. Anagen – Growth Phase
  2. Catagen – Transitional Phase
  3. Telogen – Resting Phase

Every individual strand will be at a different stage of the cycle at any one time. That’s why all our hair doesn’t grow or shed all at once. There’s a nice balance where by once cycle is complete and then new hair develops and goes through the same growth cycle. In some cases however, certain conditions can promotes hair loss by excessive shedding in one period of time.

Various Phases of the Hair Cycle are shown below:
hair growth cycle
1. ANAGEN OR “GROWING” PHASE:

This is the long growing period during which stage, the dermal papilla is attached to the follicle and hair will be growing continuously within the follicle at a certain rate. The Anagen stage for hairs in the scalp lasts anywhere between 2-6years and about 85% of hairs are going through this phase at one time. The longer the growing period the longer ones hair will grow and vice versa. Hair grows approximately 10cm per year.

2. CATAGEN (TRANSITIONAL) PHASE:

The Catagen stage is a transitional stage of a hair follicle when it goes from growth to rest. This period lasts about two weeks. At the end of the growth period, hair follicles prepare themselves for the resting phase.  What happens? The follicle shrinks to 1/6 its normal length and dermal papilla break away from it causing growth to stop. About 5% of all hairs are in this phase at any time.

3. TELOGEN (RESTING/SHEDDING) PHASE:

This is the resting period of a hair follicle and about 10% of hairs are at this stage during one time.  It is usually 3 to 4 months in length and at the end of this period older hairs that have finished their life will fall out (shedding) and newer hairs will begin to grow. The hair follicles at this stage are randomly distributed over the scalp, so that no bald spots are seen.

*At the end of the Telogen phase the hair follicle re-enters the Anagen phase. The dermal papilla and the base of the follicle join together again and a new hair begins to form. If the old hair has not already been shed the new hair pushes the old one out and the growth cycle starts all over again.

**The role of genes—hair follicles may follow a particular pattern of growth and rest. Our hair follicles are programmed to stop producing hair and spend more time in the resting stage with the progression of age.

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One thought on “The Basics: Hair Growth Cycle

  1. Pingback: Top 10 tHs Highlights of 2013 | tellingHAIRstory

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