What Is Hair?

Hair is composed of cells fused into fibres that are chemically linked. It grows from a bud or papilla and projects through the skin in the follicle (a tube-like structure leading to the skin surface). Adjacent to the follicle is the sebaceous gland, which produces the only substance – sebum – that lubricates skin and hair. Nutrition reaches the papilla via the blood, enabling the hair formation to occur. However, once the hair emerges from the follicle, its structure is stable and it no longer possesses the characteristics of living tissue, although physical and chemical processes can affect it.

Hair grows in a phased cycle, each lasting three or more years. The hair then detaches itself from the papilla, remaining in the follicle until the next hair commences growth and replaces it. The normal growth rate is 1 to 1.5cm monthly, and is slightly faster in women than in men. There are, on average, 120,000 hair-producing scalp follicles, while no new follicles appear after birth, some of those present are lost with age. Hair is continually shed at an average rate of 20 to 80 hairs each day. The growth and functions of the hair are genetically acquired and hormone controlled.

Hair has elastic properties, which are utilised in hairdressing techniques (permanently curling, tinting, bleaching and toning). A substance called ‘melanin’, introduced onto the cortex cells at an early growth stage naturally produces hair colour. It is essential to remember that a change in the hair structure will make the hair more vulnerable to the daily wear and tear of styling. More than usual care will be needed when shampooing and drying hair that has been subject to the processes mentioned. As a general rule, do not demand the impossible from your hair; let your hairdresser take into account the general condition, type and texture before styling.

Hair in poor condition requires specialist treatment. This is necessary in cases of dandruff (pityriasis) and scalp problems, which persist after using medicated shampoos. There are many general health disorders (for example, anaemia and endocrine imbalance and changes in metabolism such as those occurring during and after pregnancy) which may result in hair loss. Sudden shock, or great stress over a prolonged period, can lead to different forms of hair loss. Should any abnormal scalp or hair condition arise which causes concern, Trichological or medical advice should be sought. The following pictures are typical examples of increased fragility of the hair shaft with decreased resistance to normal wear and tear due to illness.

The hair structure is weaker at this time and with continued hair processing, such as; colouring, permanent waving, blow drying/use of tongs and irons, setting and dressing, the hair has not had a chance to recover. Hair must be treated very gently following illness. A trichologist can help by proving the most suitable applications and give advice regarding hair colour and/or permanently curling/straightening, after illness, to prevent structural damage.

Hydration (water content) is the key to skin and hair condition. Climate can have a marked effect on the drying of the skin and hair, as can an inner city environment with its associated pollutants. The hair should be washed as often as necessary. It is a fallacy that frequent washing affects sebaceous secretion: oily hair will not become oilier, nor dry hair drier. Two applications of shampoo are usually required at each wash unless the hair is washed daily or several times a week, in which case one lather is adequate. Always rinse the hair thoroughly after shampooing.