The Science of Skin and Hair

Hair has an important role in our appearance. Its functions include body temperature regulation, protection and a surface to facilitate evaporation of sweat, besides being a sense organ, just like the skin. In fact, hair is a modification of skin, growing all over our body except on our palms and soles, eyelids and lips. So it follows from this that healthy skin contributes to healthy hair.

Vidya Sury

The birth of the hair follicle

Did you know that hair follicle development starts and ends even before we are born?

The first hair follicle appears from stem cells, growing into specialized cells that turn into hair follicles when the embryo is nine weeks old. The first hair follicles appear in the area where the upper lip and chin will eventually be. Interesting, eh? And that’s the first area that comes under the razor!

By week 22, there are roughly five million hair follicles on the body and one million on the head, with one hundred thousand of these on the scalp alone. By the time the fetus is 9 months old, all the hair follicles she is ever going to have in her entire life are in place when she is born.

The life cycle of hair

The hair growth cycle follows three stages:

  • Anagen-growth phase – 2 to 8 years
  • Catagen-degradation phase  – 2 to 4 weeks
  • Telogen-resting phase – 2 to 4 months

This is a continuous process that goes on throughout the lifetime of the hair follicle. One hair cycle lasts two to eight years.  The dead hair from the catagen phase is literally thrust out of the follicle by an emerging new hair entering the growth phase. Each individual hair grows, falls and grows again – quite oblivious to what is happening with the neighboring hair. Talk about being focused!

Hair follicles on the arms go on holiday every couple of months, which accounts for the fact that the growth here is much slower. On the head, however, the hair follicles are always busy and take a vacation only once in a few years and hence hair there can grow very long.

While the hair follicle’s primary job is producing hair, recent research shows that stem cells in a specific area of the follicle can help with wound repair and maintaining healthy skin.

Why is there a variation in growth of hair across different body areas?

In boys, the appearance of body and facial hair is proportionate to the level of the male hormone as the body matures.  Androgen is responsible for hair growth all over the body. Since this is absent in girls, it accounts for the absence of heavy hair growth on their face and body. That is a good thing, or we’d all be bearded women and that would be very inconvenient!

Hair removal

While a full head of hair is invariably attractive, hair elsewhere and in the wrong places can be embarrassing. The removal of excess facial, leg, underarm, chest and back hair is popular in men and women – both for hygiene as well as aesthetic reasons. This has led to the development of a number of hair removal methods.

Smooth hairless legs and arms are definitely the goal for most women and an integral part of their beauty regime. While there are a number of ways to achieve this, shaving continues to be the most popular simply for its sheer convenience of being able to grab one and go.

Healthy skin and hair indicate overall good health. Changes in the skin and hair are warning signs of a health problem. Conditions like diabetes and thyroid disease cause hair loss. Dry skin leads to dry hair. A vitamin deficiency quickly shows up in the quality of skin and hair. You might call them best friends forever, since any issue with the skin will have a direct impact on hair.

Editor: Head over to the conversations with the lady from Gillette @ Myths and facts about Hair Removal!

Vidya Sury is a happy work-at-home Mom, a freelance writer, business blogger, health blogger and social media enthusiast. She loves DIY, Coffee, Music, Photography, Family, Friends and Life.  She believes that Happiness is a DIY Project. She blogs at and tweets as @vidyasury

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