Hair Care

Mixed Hair Types & Straight Hair | Curly Hair

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Over many thousands of years these three groups of people have intermingled. Their descendants now show every imaginable blend of hair type and color.

Of the three racial groups, the Caucasoids are by far the most varied in the appearance of their hair. It may fall completely straight, it may be crinkly or wavy, or it may form large curls, or pretty well anything in between. Blondes tend to have straight hair, while more brunettes have curly hair. The longer the hair grows, the more obvious its basic character becomes. The first month or two's growth of a new hair may be straight, but then it may start to curl or wave.

Types of Hair Variations

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Scientists do not fully understand why the different types of hair growth have Straight Hair, Curly Hair, Wavy Hair, Greasy Hair or Dry Hair. This is probably determined by several factors, which may vary in their importance during life. This is why some curly-headed children have straight hair later in life, and vice versa. These factors include:

The way the large bundles of keratin are arranged within each hair shaft

The position of the hair bulb in the hair follicle - in African hair the bulb may lie to the side of the follicle, and so the hair shaft grows out of the follicle at an acute angle

Irregular growth in the hair bulb - if it varies slightly to one side or the other the hair may grow wavy

The shape of the hair follicle, whether it is straight or curved

The number of twists per unit length

All hair, even the apparently perfectly straight hair of Asian people, twists as it grows. The number of twists in a given length of hair determine how curly it is: the more twists there are, the curlier it will be. Some African hair has 12 times as many twists per centimetre as Caucasian hair.
In Asian people the keratin bundles in the hair are all straight. The hair shaft tends to be thick, and almost completely round.

The keratin bundles in the hair of Caucasoid people are a mixture: most are straight, some are wavy. The proportions of the two types vary a lot. The hair shaft is usually oval in shape.

The tightly curled hair of African people twists much more frequently than in the other groups. The hair shafts are markedly oval in shape, with definite edges. The cuticle is sharply kinked at the edges, and is especially easily damaged at these points. This curious shape is the reason for the vulnerability of African hair to all forms of physical and chemical trauma, and its consequent need for extreme care in handling and very thorough conditioning.

Straight hair sometimes becomes quite wavy when damp, and wavy hair may become straight when thoroughly doused with water - in a swimming pool, for instance. This is because in these conditions great numbers of hydrogen bonds have been broken. The effect is very temporary, and the hair recovers on drying

Asian Hair & Caucasoid Hair & African Hair

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Asian Hair people are from the Orient, for example from China and Japan. Their hair is very straight, and always black in color.

The Caucasoid group is the most 'varied' of the three racial groups. Modern Caucasoids are very varied, even though they are descended from the same group of ancestors. They range from the fair-skinned people of north-west Europe to the widely varying peoples of the Indian subcontinent.

Caucasoid Hair may be either wavy or straight, and the diameter varies widely too. The color ranges from black to a pale blond that is almost white, including just about every possible shade in between.

African people originated in Africa. African hair is black and tightly curled. It tends to be woolly and dry, and is extremely easily damaged by heat or chemicals.

Different Types of Hair

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The range of different types of hair is enormous, ranging from tight wiry curls to ruler-straight. The color and shape of hair vary too. What accounts for these differences?

The type of hair you have is inherited from your parents. We may look back further, and say that it is determined by the part of the world in which your ancestors originated. It all depends on the race, or mixture of races, from which they came.

In the very earliest days of human evolution, three basic racial groups of people seem to have existed on this planet. These spread out across the world and became mixed together. They are especially well mixed in countries where there has been massive immigration, such as the U.S.A. over the last few hundred years.

Scientists have identified three basic types of hair in today's human population, and have related them to these three early races: Asian, Caucasoid and African. The three types of hair not only look quite different, but the differences in their responses to physical and chemical damage can be remarkable.

Hair Texture

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Much of the attraction of a beautiful head of hair lies in its texture, or feel. The texture of hair depends on several things.

The first is the average diameter of the individual hairs. We have seen that these vary widely. The larger the hair diameter, the coarser it will feel.

Secondly, different people's hair naturally feels different: some hard and others soft, some silky and others wiry. The reasons underlying these differences are still a matter for scientists to argue over.Thirdly, the texture is affected by the degree of weathering of the hair.

Finally, hair texture is affected by what has been put on it. Repeated lavish applications of hair spray gives hair a different feel from that of hair that has been freshly washed and conditioned. Conditioners make hair feel soft and smooth. Conditioners that contain silicones even give a slightly different feel from those that don't (most manufacturers do put silicones into conditioners nowadays, however, as they protect the hair cuticle). Contrary to popular belief, this altered feel is not a sign of build-up.

Hair Diameter & Hair Porosity

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The elastic properties of both wet and dry hair are related to the diameter of the hair shaft. The thicker the hair, the more it will tend to resist stretching

In a normal, undamaged hair shaft, very little water can get either into or out of the cortex. This is because the cuticle covering the cortex is intact, and is then almost (but not quite) waterproof. Shampoos do not damage the cuticle. When hair is permed or tinted, however, the chemicals have to penetrate the cortex in order to react with the keratin inside it. Increasing the temperature, or applying an alkaline lotion, separates the scales of the cuticle enough to allow the chemicals to pass through. After the processing is finished the scales gradually close up again.

But if hair is processed too many times the cuticle scales may never return to their original tightness and the protection they once offered is lost. The cuticle can also be damaged in the same way by too much blow drying, curling irons that are too hot, and the effects of wind and sun. The hair becomes increasingly porous, and water can then pass in and out of the cortex.

Over-porous hair is dry, and tends to develop split ends. The damaged cuticle is fragile, and the damage worsens as time goes by. The greater the damage, the more the cortex swells with water whenever the hair is washed, but the more water it loses when it dries. The repeated wetting and drying of the cortex gradually weakens the hair.

Hair Moisture

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The moisture content of hair is greater when the atmosphere is moist and humid, and less when the air is dry.

The reason why hair 'collapses' in hot, humid atmospheres is summed up by:
heat and humidity -> more moisture
-> less static electricity
-> collapse
In dry conditions:
heat and dryness -> less moisture
-> more static electricity
-> more volume (body)

When hair is wet the cortex swells and the edges of the cuticle scales tend to lift. The hair surface temporarily loses its smoothness.There is therefore more friction when wet hair is rubbed than when it is dry. This is what can lead to matting and tangles developing during over-vigorous shampooing (there is not greater static charge on wet hair than on dry).

These tangles are one of the reasons why many children hate having their hair washed, and the problem is easy to avoid.

Hair Static Electricity

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When dry hair is rubbed, as it is whenever it is brushed or combed, static electric charge builds up on the hairs. This is especially noticeable in hot, dry weather. The charges tend to push each other apart, and as a result charged hairs can never lie smoothly against each other. The result is 'fly away' hair, which stands out from the head and looks unmanageable.

Conditioners, and shampoos with high levels of conditioning agents in them, leave the surfaces of the hair smooth. There is therefore less friction when the hairs are rubbed: hence less static electricity builds up on them, and 'fly away' is reduced

Hair Elasticity

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This is one of the most important properties of hair. Because of its elasticity, hair can resist forces that could change its shape, its volume or its length. Its elasticity lets it spring back to its original form without damage.

When healthy hair is wetted and stretched, it can increase in length by up to 30% and still return to its original length when it is dried. Stretching it more than this will tend to damage it, however, leading to permanent lengthening and even breaking.

The elasticity of hair depends on the long keratin fibres in the cortex. Chemical treatments of hair such as perming and bleaching can alter the cortex after repeated damage, and change the hair's elasticity. Hair with poor elasticity will stretch only to a limited extent. It will not curl, it will break easily when it is groomed and it cannot be permed satisfactorily.Both natural sunlight and artificial ultraviolet light break down chemicals in the hair and damage its elasticity in the same way that bleaching does, though to a much lesser degree.

A stylist must always examine the elasticity of a client's hair before deciding on any chemical procedure.

Physical Properties of Hair

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Hair can be stretched, bent and curled. It can absorb moisture or lose it. Its behaviour can alter when it is wetted or when it is brushed. We look at the special properties of hair, such as its elasticity, porosity and texture.

Understanding these properties is important for all of us as we cope with our hair under different circumstances. It is especially important for the hair stylist who has to decide on styles and to suggest continuing hair care regimes for clients.

Closer Hair Check

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Hair stylists and technicians examine the whole head of hair as part of their everyday practice. Matters to note include racial type, hair length and hair thickness, and if there is evidence of weathering, of previous cosmetic treatments such as perming and tinting and of accumulated hair spray.
A closer examination of the roots under a good light usually indicates the real state of the hair. The first centimetre or two of growth may look very different from the rest. This could indicate a change in the treatment that the hair has received, perhaps to a persistently harsh regime.

Next comes a look at the individual hair shafts with the naked eye. This may not reveal much, unless there is unusually serious damage. In very long hair that has weathered, the end may look a different color from the rest, or perhaps less glossy. This is almost certainly the onset of split ends.

Under the microscope, however, a very different picture may emerge. Hair scientists use both ordinary microscopes and electron microscopes to examine hair in the laboratory. These allow them to understand what happens to hair when it is heated, permed, tinted and so forth. You will find examples of what can be seen under both kinds of microscope throughout this book.

Loose Hair

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Many people worry because they often find loose hairs on their clothes, or after shampooing, and they become terrified in case they may lose some or most of their hair.

If you pull the hair lightly with your hand, you may well find that a few hairs do come out. These are almost certainly hairs that are ready to fall anyway - telogen hairs. You can confirm this by looking at the roots in a good light. A telogen follicle root is a little hard, white bead. Brushed-out hairs all have this kind of root.

On the other hand, the root of a hair that is pulled out is fat, soft to the touch and sticky - it will stick to your hand, because it still carries fluid from the follicle. And pulling it out hurts! This is an anagen hair, one which was not ready to be shed.

Hair Check

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From time to time doctors, scientists, hair stylists and technicians are all asked, for different reasons, to examine someone's hair. All of them need to know the right methods to use, and to understand the hair growth cycle and the cosmetic treatments and weathering processes that affect the hair's appearance

Hairlines

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Forehead hairlines are determined genetically. The hairline that you were born with may well be the one you ultimately have in your adult life. Nearly all women keep their frontal line unchanged from childhood to old age, although some women's hairlines may seem to recede because their hair gets thinner. About half of all men may expect the hairline to recede to some extent, however.

Hair Stream

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A hair does not grow straight up out of the skin, but leaves the follicle at a definite and predetermined angle. This angle determines the direction along which the hair will lie, and determines the patterns or streams that the hairs make on the head. Often the streams spiral outwards from a central point (or points) on the crown of the head. Usually these spirals, or 'whorls', run in a clockwise direction.

The classical 'cowlick', seen in around 7% of children, is due to a particular hair stream on the forehead. Unruly hair in children may be the result of scalp hair patterning. Another possible reason is an unusual structure of the hair shaft.

Hair Growth in Puberty

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At puberty the immature vellus-like hairs on our bodies can change to terminal hairs. This change results from the dramatic rise in androgen levels at that time. It is especially noticeable in young men. Young women who suffer from the condition of anorexia nervosa, however, stop having periods and produce very little oestrogen: their natural androgens tend to thicken their fine vellus-like hairs in the same way.

The effects of androgens continue long after puberty. Some areas of the skin respond to these hormones more vigorously than others do, and at different times of life. Pubic and armpit hair begins to grow at or soon after puberty. Most men's beards do not grow strongly until the owners reach their thirties. The growth of chest hair reaches a peak even later, and hair in the nose and ears grows most in late middle age.

Scalp Hair

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The hair of the scalp is, however, most sensitive to the effects of male hormones (androgens), which are in the blood of people of both sexes (only in different proportions in men and women). Androgens are the most important factor regulating hair growth, and also the thickness of the hair shaft. Female hormones (oestrogens), which both sexes have too, slow down hair growth during the growing period but also make that period longer. Many women notice a difference in their hair growth during pregnancy. At this time women have vast amounts of oestrogen in their blood, far outweighing their male hormones. It is the balance between the male and female hormones which decides the growth of the hair.

Vitamins for hair growth

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Some Vitamens may be particularly important for hair growth. For example, some people who lack zinc in their diet produce only fine, sparse hairs and even lose their hair. Vitamin B, also known as panthenol, plays a part in hair growth. It also improves the physical properties (elasticity, strength and gloss) of the hair shaft.

The hair cycle for each individual hair is influenced by the levels of various hormones in the blood. Thyroid hormone speeds up growth in resting hair follicles. Steroids taken by mouth slow it down, though steroids inhaled for the treatment of asthma do not affect hair growth.

Hair Growth | What controls Hair Growth

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No one can answer this question with certainty. What we do know is that it takes a lot to stop hair growing!
General health and nutritional factors are increasingly believed to be important for healthy hair growth. We do know that serious anaemia affects hair growth. So too does starvation: people who go on a crash diet may start to lose their hair some six to ten weeks later. Many alcoholics have poor hair growth or even hair loss because their way of life tends to lead to malnutrition.

Hair Length

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How long anagen lasts is determined genetically, and varies between the sexes and from one person to another. It is the length of this time that decides how long the hair will grow before it falls out. Anagen lasts between three and seven years in most people.

As we have seen, a hair grows at a rate of about 1centimetre a month.

After one year it will be 12 cm long. After five years it will be 60 cm long.

Waist-length hair is 80-90 cm long, and will have taken about seven years to grow.

Shoulder-length hair will have taken only about three years. Thus only people with long anagen times can expect to grow their hair down to the waist.

As people grow older the period of anagen shortens. For example, the hair of someone with a five-year anagen can grow to a length of 60 cm before it enters the shedding phase. If their anagen period drops to three years as they age, their hair will then grow only to shoulder length before it falls out or is brushed out. So when a scanty-haired elderly lady boasts that when she was a girl she could sit on her hair, she may very well be telling you the truth!

Telogen (The Shedding Phase)

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The telogen phase lasts for three or four months. This is the time at which a new hair begins to grow from the hair follicle. As it grows upwards the old hair will be shed naturally or may be pulled out, which happens easily and painlessly with telogen hairs. These are the hairs that come out when you shampoo or brush your hair.
Shedding is part of the normal process of the replacement of old hair with new. At any one time, around one in ten of the follicles on an individual's head are in the shedding phase.

The new hair emerges from the same opening at the surface of the skin as the old one, and the hair cycle begins again.

Catagen (The Intermediate Phase)

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The anagen phase is followed by a short resting phase. This catagen phase lasts for between two and four weeks in the human scalp. No pigment is made during that time, and the follicle stops producing hair. The base of the follicle moves upwards towards the surface of the skin.

Anagen (The Growing Phase)

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The anagen phase of a new hair starts at the moment it begins to grow. At that time there is very active growth in the hair bulb. This usually lasts for some years, generally between three and seven, without interruption. Since human hairs grow at a rate of roughly 1 centimetre a month, hairs can grow to a length of a metre or so.
As we have seen, hair may grow more quickly in winter than in summer. Hair growth varies with the season as a result of a change in the difference between hair follicles in the growing and shedding phases.

Pigment (melanin) is made in the hair bulb throughout this phase of the hair cycle. Less pigment is made in the hair of older people. This is why white hairs start to appear, even though the hair itself may still be growing strongly.

In some older people the hair cycle becomes shorter, the follicles gradually give up producing long, strong hair, and the hairs become thinner and shorter. The result may be a general thinning of the hair, or even a degree of baldness

Stages of the Hair Cycle

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Between starting to grow and falling out years later, each hair passes through three distinct stages. These are so important that they have been given special names:

Anagen (the growing phase)

Catagen (the intermediate phase)

Telogen (the shedding phase)

We shall look at these three stages in turn.

The Hair Growth Cycle

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Each individual hair is formed inside a hair bulb deep in a hair follicle. The follicle is a tiny but powerful factory, which throughout many people's lifetime hardly ever stops working. From a baby's birth for many decades, as much as a century in some people, the follicle continues to produce hairs. Each hair grows for many years: during this time it will be shampooed, conditioned, cut, blown dry, exposed to sun and wind, colored or bleached or permed. None of these treatments affects the growth of the hair in the hair bulb, even though some may seriously damage the hair shaft. Finally the hair spontaneously falls out. The follicle rests for a little while, and then starts to produce yet another new hair. This is the hair cycle.

You need to know about the hair cycle in order to understand many of the problems people have with their hair. These can range from the sudden appearance of hairless patches to complete baldness in men, and sometimes in women too.