Skin and hair are connected intricately. Here are some hair facts.
Hair has an important role in our appearance. Its functions include body temperature regulation, protection, and a surface to facilitate the 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.
5 Hair Facts You Should Know
Hair facts: 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. There is a pattern to this. 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!
Hair follicles on the body, face, and scalp begin in the fetus at 4-5 months. 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’s born, she comes into the world with all her hair follicles – no additional ones will develop.
Hair facts: 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!
The hair follicle is in constant touch with every cell of the body via biological signals and its blood and nerve supply. This tells it when to produce new hair, when to rest and when to shed hair. This whole process depends on the androgenic male hormone testosterone, thyroid hormone, and female hormone.
Hair facts: So why does hair thin out?
Simple logic: As we grow from childhood into adulthood, our scalps expand. There are also genetic factors involved.
It is normal for a healthy person with a good mane of hair to shed 50-100 dead hairs per day, so don’t panic. Hair fall can also be affected by age, hormonal changes, nutrition, skin disease, and stress, besides other external factors such as medication, treatment, radiation, and exposure to chemicals.
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.
Hair facts: Why is there a variation in the 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 faces and body. That is a good thing, or we’d all be bearded women and that would be very inconvenient!
Then again, the hair on the head does not depend on androgen! Yet this hormone plays a role in permanent scalp hair loss leading to a condition called “Androgenetic Alopecia”
While hair follicles on the face, torso, arms and legs and scalp depend on androgen for growth and development, follicles at the top, front, and sides of the scalp may stop functioning because of specific testosterone.
Hair facts: 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.
While visible hair above the upper lip or chin in the form of a mustache and beard may be great for men, it is not welcome in women. Thick eyebrows may be perceived as adding to the character in men but can look unkempt in women. Thick underarm hair growth is undesirable in both sexes.
Aesthetics-wise, smooth hairless legs and arms are definitely the goals 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.