Updated 08 January 2016

Interesting facts about your hair

Having a bad hair day? Most women spend inordinate amounts of money on their hair, but how much do they really know about their tresses?


One only has to look at the amount of money spent on advertising hair products to know how important a role hair plays in how women feel about their appearance.

Inordinate amounts of cash gets spent to avoid those bad hair days – hair colourant, mousse, gel, shampoo, conditioner, straightener all promise to do just that.

But how much do we really know about our hair?

The facts

It has been estimated that the average person has about 100,000 scalp hairs. Each hair grows from a papilla, or a bulb-shaped root, planted slightly below the surface of the skin.

A single hair has three layers: the cuticle, the cortex and the medulla. The cuticle is the outermost layer in which thin cells lie over each other like scales; the cortex which gives the hairs its form, colour and body and the medulla, the innermost core, which does not usually extend right to the end of the hair.

Hair grows from hair follicles, which are usually set at a slight angle. Each hair follicle has a tiny muscle attached, which contracts when you are cold or excited, causing the hair to stand on end.

Hair grows between 1,5 to 3 mm per week. Scalp hairs live from two to five years, eyebrows and eyelashes from three to five months.

Straight hair has round hair shafts, wavy hair has kidney-shaped hair shafts and curly hair has oval hair shafts.

All the hair follicles you have, you are born with. Normally you lose between 30 and 100 hairs per day from your scalp.

Hair grows in cycles. There is a growth period – usually about about three years, and a rest period – usually about three months – and then the hair falls out. A new hair then grows from that follicle.

Hair damage

Constant blowdrying, frequent perming and colouring are all things which could damage your hair and cause the ends to split or the hair to break or even fall out. It is best to let professionals do these treatments, as things can go wrong when you try these at home by yourself.

Hair colour

Hair colour is produced by a pigment in the cortex layer of the hair. This pigment originates in the hair follicle. It is not known why hair follicles stop producing pigment.

Function of hair

Hair serves various functions. It holds in body heat in cold weather and it insulates the skull from the heat of the sun.

Eyebrows prevents sweat from dripping into your eyes. Hairs in your nose and ears filter out foreign materials such as dust, pollen and small insects. Eyelashes serve a similar function.

 Looking after your hair

Hair should be kept clean, but should not be washed more often than once every two days. It should be washed at least once a week. Hair is fragile when wet and should be combed very gently, otherwise the hairs will split. Frequent brushing has the same effect.

Common hair problems

Dandruff is a common problem, but most dandruff can be controlled with medicated shampoos. Baldness can be caused by burns or scars that kill hair follicles. It can also be a side effect of psoriasis allergic reactions, dermatitis and emotional stress. When the condition disappears, hair will usually grow back again.

Male-pattern baldness is mostly a hormonal phenomenon and appears to be hereditary. There does not seem to be a cure for this, despite claims made by the purveyors of lotions and potions.

Hair transplants seem to be the only long term solution.


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