ALL ABOUT HAIR

This section explains, in simple terms, how hair grows, the different types of hair loss and what causes them, as far as we know. Hair grows from all parts of the human body, except the palms of our hands and the soles of our feet.

Hair Growth

The Diagram below illustrates the main components of a single hair and indicates their functions.

The hair grows outwards from its follicle by multiplication of cells in the root. The main component of hair is keratin, which also forms the principle matter in nails. The root of the hair is embedded in the base of the follicle and is interconnected with the papilla and through it with the vascular and nervous systems of the body.

Hair growth occurs in a regular cycle. The growth phase is termed the anagen and lasts between 11/2 and 7 years. This is followed by the catagen phase, which is when the hair stops growing and detaches itself from the base of the follicle. Once it has done so it is called a'club' hair. Finally, the telogen phase is a resting period lasting about three months before growth resumes.

At any point in time, about 85% of the hair is in the anagen phase, 1% in the catagen phase and 14% in the telogen phase. When the cycle re-starts, the new hair may have to push the old hair out of the follicle, which is why, sometimes, two hairs can be seen in the same follicle.

Hair Loss

We lose hair continuously, normally at the rate of sixty to one hundred hairs per day, although the rate varies with the seasons. The lowest losses occur in the summer. The normal number of hairs for an adult is about 100,000 with blondes typically having more and redheads fewer.

Baldness starts to occur when the rate of hair loss exceeds the rate of growth.

Because the hair relies on the efficient functioning of the nervous and circulatory systems, dysfunctions in these systems will tend to have an effect on hair growth. Good general health is therefore an important contributor to healthy hair growth. There are a number of different types of hair loss and the next section examines the most important ones and their causes.

Types of Hair Loss

The general term for hair loss is Alopecia and there are a number of generally recognised types which are caused by different factors from physical abuse, through heredity, to illness and disease. Also, although some are common to both sexes, others afflict only one sex. Each of the most common types is reviewed below.

Alopecia Androgenetica

Commonly referred to as 'male pattern baldness', this is by far the most common type amongst men. It is thought to be responsible for about 95% of baldness in males. It is manifested by a receding hairline combined with loss of hair from the crown. The condition can occur from the late teens through to old age but generally appears by the late thirties. There is typically a genetic pre-disposition to male pattern baldness but the physical causes are known and can often be addressed. Women can also suffer from Alopecia Androgenetica when they reach menopause but in much smaller numbers (about 15%).

Those suffering from Alopecia Androgenetica experience a shorter anagen phase and the new hairs become progressively shorter and finer. Eventually, the follicle shuts down completely leaving the whole area bald.

The fundamental cause of this condition is a set of chemical reactions. Testosterone produces a derivative called dihydrotestosterone (DHT), caused by a reaction between the testosterone and sebum, the naturally occurring oil secreted by the skin tissue. DHT enters the hair follicle and in those with a genetic pre-disposition to hair loss, it reacts chemically in the follicle and gradually destroys the hair root. There are thus three ways to deal with the problem :

1. Control the creation of DHT
2. Remove DHT from the scalp before it enters the follicle
3. Clean the DHT out of the follicle before it does any damage.

Drugs are available that operate the first way and can be very effective. However, in some cases, they have some very undesirable side effects such as impotence and some cannot be used by women. BIOSCAL works in the second and third ways, with no side effects.

Alopecia Areata

This type of hair loss refers to patches where the hair has fallen out by the root. The areas sometimes join up and form large areas of baldness. It can occur on any part of the head and can appear very suddenly. Sometimes the hair will re-grow quite quickly. The causes are variously thought to be genetic, stress related, or the result of a disease or immune deficiency, so a doctor's visit is the first priority to establish that an identifiable physical problem is not the cause. Probably related to Alopecia Areata are two more extreme conditions, the loss of all scalp hair (Alopecia Totalis) and the loss of all body hair (Alopecia Universalis)

Diffuse Alopecia

Diffuse Alopecia refers to a gradual thining of the hair specifically in females. There are a wide variety of possible causes and medical advice should be sought to identify the specific problem. Some common ones are moulting following child birth, stress, fever, problems with the pituitary or thyroid glands, iron deficiency or anti cancer drugs.

Traction Alopecia

Traction Alopecia is caused by too much stress being placed on the hair and again is found primarily amongst women. It can be the result of rough brushing, tightly pulled ponytails or braids, hair pins, curlers or just excessive blow drying.

Other types of less common Alopecia are Cicatricial Alopecia (due to scars), Alopecia Adnata (baldness at birth), Alopecia Follicularis (follicle inflammation), Alopecia Senilis (old age), Alopecia Neurotica (nervous disorder), and Tricchotillomania (pulling out own hair).