Hairs are thin fibres made mainly of a protein called collagen. The hair sticks out from hollow tubes, hair follickles, originating in the fat layer just under the skin and going through all structures of the skin out to the surface.

Lengthwise the hair is composed of three sections. The root is the deepest laying section. This section contains living epitelial cells that constantly divide so that new cells are pushed upwards. Also a small blood vessel go in and out under the middle of the root that futnishes the deep part of the hair with nutrient and oxygen. At the under-side the epitelial cell layer is folded up as a pocket and the blood vessels and also nerve fibres enter up into thet pocket.

This pocket with its content is called the dermal papilla. This is the main cell producing part of the hair. All cells that divide and produce the hair originate from cells originally produced in the dermal papilla.

As the new cells are pushed outwards they are gradually filled with keratin, dries out and die.

The next section is a thickened portion called the bulb laying within the skin. It is in this section that the cells are transformed from living cells to dry elements mostly containing keratine.

The longtest section is the visible hair that sticks out from the skin, composed entirely of dead cells made mostly of keratine.

In cross-section, the hair is composed of several layers with cells arranged in different fashion and with somewhat different chemical composition. The innermost layer is the medulla. This layer can be lacking and instead there can by a hollow space in th emiddle of the hair.

The next layer is the cortex. This layer is a compact and strong structure where also the color elements recide. Then there are several layers of various composition and geometrical structure. The outermost layer is the cuticle that serves to protect the hair.

The molecules of the protein keratin are lang fibres. These fibres are cross-linked with di-sulfide-bridges. This is sulphur atomes from two fibres making bonds with each other. This cross-linking makes the hair strong, and also define the appearence of the heir, for example if the hair is curly or not. Some people have somewhat flattened hair. Hair of this type also tend to be curly.

The hair follicle is a pucket made or epitelial cells that goes downeard from the skin epidermis, through the connective tissue layer of the skin- the dermis and ends just under the dermis in the fatty area - sub-dermis. The hair follicle is actually continuous with the epidermis and contain epitelial cells of the same type. The substance keratine is actually the same substance that covers the outer skin surface.

Around the hair follickles there are small glands that produce a blending of vaxes and oils, sebum, that is emptied into the hair follicles and that lubricates the hairs and the skin. These glands are small sacks with walls composed of epitelial cells. Inside the walls are glandular cells that constantly divide and are producing sebum. The new cells are gradually filled with sebum at at last they burst and empty the sebum into the hair follicle.

Each hair have a growth cycle. In the beginning only the dermal papilla and the pupper part of the hair follicle are present.

In the anagen phace, cells are produced from the dermal papilla. The full structure of the hair follicle is produced and the hair grows out.

In the catagen phase the middle and most of the lower part of the hair follicle is destroyed and the dermal papilla is left without connection to the heir.

In the telogen phase all activity in the hair and dermal papilla is resting, and eventually the hair falls out.

The color of the hair is produced by cells in the hair follicles, the melanocytes. There are mainly three types of color substances: The red substance pheomelanin, the black eumelanin and the brown eumelanin. The amount and mixture of these substances determine the hair color.

There are mainly two genes that dentermine hair colors. One of the genes has a variant that command production of the red color pheomelanine and one thet do not command such production. The last one is dominant so that both genes in each gene pair have to be of the ffirst type for a person to have much red substance in the heir.

The other gene determine if the person shall produce much dark pigment, eumelanine, or only little of it. The variant that command much dark pigment is dominant.

The common form of hair loss, as seen by many men, and to some women to a less extend is caused by hereditary susceptibility towords an altered form of the male hormone, testosterone, called dihydrotestosterone, and perhaps also an excess production of rhese hormones that is also genetically inherited.

Every person sheds some hair every day, as can be seen when one washes the hair and finds a few hairs left in the basin afterwards. This hair will in time be replaced from the hair root with new hair that normally is as strong as the hair shed. The hair root is not shed. The small white bobble on the end of the hair is not the hair root, but is made up of degenerated cells from within the hair root and is called the club. If it were possible for a hair to be pulled from the scalp bringing a hair root with it, then the scalp would actually bleed.

If dihydrotestosterone has been produced the new hair comming out will gradually be thinner and shorter. This means that the new hair growing through will be finer. When this new fine hair is later shed the Dihydrotestosterone again miniaturises the follicle and hair root even further and hence the next hair will be finer still. This process will continue until the hair is so fine that it may as well not be there at all and if this happens over an area, then the man will obviously thin over that area and hence baldness occurs.

You can usually tell when a person is thinning on the front hair line by feeling the thickness of the hair and comparing it with the hair at the back of the head. It takes a bit of skill but eventually you should be able to tell just by touch when the hair is starting to thin.

Patterns of hair loss

The pattern of hair loss differs between men and women.

Hair loss aggreviated or caused by drugs

Also use of certain drugs aggraviate or causes hair loss. The following is a list of drugs know to cause hair loss in certain cases:

Cholesterol-lowering drug:

clofibrate (Atromis-S) and gemfibrozil (Lopid)

Parkinson Medications:

levodopa (Dopar, Larodopa)

Ulcer drugs:

cimetidine (Tagamet), ranitidine (Zantac) and famotidine (Pepcid)

Anticoagulents:

Coumarin and Heparin

Agents for gout:

Allopurinol (Loporin, Zyloprim)

Antiarthritics:

penicillamine, auranofin (Ridaura), indomethacin (i\Indocin), naproxen (Naprosyn), sulindac (Clinoril), and methotrexate (Folex)

Drugs derived from vitamin-A:

isotretinoin (Accutane) and etretinate (Tegison)

Anticonvulsants for epilepsy:

trimethadione (Tridione)

Antidepressants:

tricyclics, amphetamines

Beta blocker drugs for high blood pressure:

atenolol (Tenormin), metoprolol (Lopressor), nadolol (Corgard), propranolol (Inderal) and timolol (Blocadren)

Antithyroid agents:

carbimazole, Iodine, thiocyanate, thiouracil

Blood thinners, male hormones (anabolic steroids)

If in doubt always ask your doctor to look up know side effects on any medication you are taking

Alopecia areata

Alopecia areata, or patchwise hair loss, is an autoimmune disease where the body's immune system is attacking hair follicles and make them go into the rest stage with hair falling off. One usually count on three stages of hair loss:

The disease can appear in three distinct ways:

- Patchy heir loss, mostly on the scalp

- total hair loss on the head

- total hair loss on the whole body


The disease is often relapses alternating with periods of hair loss and hair growth. Generally, the more hair one loses the more likely that it never grows back. In some patients also suffer from problems with nail structure, making them brittle. The disease is not physically harmful but can be very psychologically distressing for the victim. Many people with Alopecia choose use a wig.


It is sometimes associated with other autoimmune diseases such as Vitiligo (white patches of skin) and hypothyroidism (underproduction of thyroxine in the thyroid gland).

Treatment with steroid drugs injected into the hairless regions may help to moderate the immune system in these areas and help hair come back. Systemic steroid treatment may give the same help, but such treatment have too great side effects to be practically useful in most instances.
 

Modulating the immune system and stimulating the hair growth with vitamins, minerals, antioxidants and herbs may be of help.

Most people loose color in their hair and get grayish, gray or even white hair, even though the degree or graying can vary very much. The graying is however not merely a loss of colo0r. Such a loss would produce blond hair, and not graying. Some light-skinned and blond children have nearly white hair, but it is still very different from gray or white hair caused by aging or diseases.

The main reason for graying is the dying out of the cells in the hair follicles producing hair color, the melanocytes. This occurs gradually as one ages. One other possible reason are structural chages in the hair causing the hair to contain more air.

The rate of disapparance of the melanocytes is dependent of the genes. Some people tend to get gray hair very early, why others can keep their hair color very long.

However, the vitality of the melanocytes is dependent upon the nutritive status of a person. Persons suffering from grave malnutrition will sometimes get gray hair very fast.

Hypothyroidism, a condition where the thryoid gland do not produce enough thyroid hormone, will often cause garying of the hair. Diabetes type II also tend to cause faster loss of hair color. The habit of smoking tend to accelerate hair graying very much.

Sunshine can bleach the color of the hair, but will not affect the production of pigment by the melanocytes.

The loss of hair color may not be permanent. When a component of the cause is malnutrition or disease, or smoking, the color can come back when that factor has ceased.

The effect of some factors can stimulate the melanocytes to new vitality. The hair can get new color after inflammatory porcesses. The same can occur after radiation and after therapy with cytostatica. Cytostatica will often cause hair loss, but when the hair grows back, it will sometimes be more vital and get a darker color.

Up to top