In This Article

• Hair Structure
• The Hair’s Growing Cycle
• Stages in the Growth Cycle
• Types of Hair Loss
• Reasons for the hair loss defined
• Hair Loss Patterns In Males
• Hair Loss Patterns in females

Hair Structure

The basic structure of hair is keratin, a strong protein that is the basis of hair, nails and the outer layer of skin. Each individual hair is made up of three layers.

• The Medulla is the innermost layer of hair, which is only present in large thick hair
• The cortex is the middle section, which gives the hair its texture and colour.
• The outer layer is the cuticle and it is a clear, thin layer whose only function is to protect the cortex.

Below the surface of the scalp lies the hair root, where all hair growth begins. This root nestles in the hair follicle, and at the base of the follicle is the dermal papilla. The dermal papilla produces new hair growth by using nutrients it obtains from the bloodstream.

The dermal papilla is also important, as it is a receptor for the androgens, which are the male hormones. It is the androgens in males that generate hair growth. Hair thinning, or hair loss can be traumatic, especially for the young. It can be defined as shedding hair follicles all over the head, or in a specific patch, when it is known as alopecia.

The Hair’s Growing Cycle

Human hair grows in a cycle, which typically lasts for about five years; a natural part of that rhythm is shedding hair. The average scalp has 100,000 hairs, and it is normal to lose 100 every day. Typically a natural blonde has about forty percent more hair than a brunette, and a red head has the least of all. Hair shedding must be taken in proportion, if you have a lot of hair on your head, then the normal rate of shedding is higher than someone with fewer hair follicles.

Stages In the Growth Cycle

• Anagen, Growth Phase

Approximately 85 percent of the hair on your head is in the growing phase at any given time. This phase can last from between two to six years. Hair can grow at the rate of approximately 5 inches per year. Each hair has a maximum length, and it is not normal for any one hair to grow to a greater length than a meter.

• Catagen, the Transitional phase.

When the Anagen growth phase comes to an end, the hair enters into a Catagen phase which can last between one and two weeks. During this transitional phase, the hair follicle shrinks to about 1/6th of their normal diameter. This squeezes the hair root deep within the hair follicle and the dermal papilla breaks away and rests below the scalp.

• Telogen, or Resting Phase.

After the catagen phase, hair goes into a resting phase known as telogenic period. This period can last from five to six weeks. The dermal papilla is still in a resting phase below the scalp, which means the hair does not grow. Approximately 10 to 15 percent of all hairs are in this phase at any one time. When this stage comes to the end of the cycle the dermal papilla and the base of the follicle join together again, and the hair can enter into the growth phase. Sometimes the old hair has not fallen out and the new growth has to push it out of the hair follicle.

Hair does not go through the hair growth cycle in patches or patterns. Each hair can be in a different stage of this cycle compared to the adjacent hairs. Which means there no pattern on the head that is discernible by sight, to the naked eye.

As we age we all lose both hair and thickness and lustre. One in four men display a sign of baldness by the time they are in there thirties. For some people, the shedding of hair is more marked, and whilst the majority of sufferers’ are men, it can affect women and children.

Hair loss may be temporary or permanent. For instance if you have a traumatic mental shock, or are physically ill, it would not be unusual for your hair to fall out about four months later. If you are about to be ill your hair can fall out, it is often an early sign of lupus or adult onset diabetes.

Hormonal imbalances can cause hair loss. When the thyroid malfunctions, either by over productivity or by under productivity, temporary hair loss is usual. Also the sex hormones, the androgens in the male and the estrogens in women can cause havoc on your head. Under normal conditions when the root cause of the hormonal imbalance is treated the hair growth quickly returns to its normal pattern.

Another instance that a hormonal change can affect the growth of hair is pregnancy; it is fairly typical that the hair falls out when the baby is about three months of age. When the bodies’ pre pregnancy hormonal level is reached, the hair recovers.

Some medicines can cause hair loss; this is temporary and ceases when you stop the medicine. Chemotherapy medication, the birth control pill, gout medicines, anticoagulants, antidepressants, and an overdose of vitamin A in tablet form, are amongst the drugs that can affect the hair.

Fungal infections such as ringworm can cause the hair to be lost, especially in children. Hair loss can be an early symptom of disease, however it is vital to be aware that hair loss is never the only symptom. It is always accompanied by more specific symptoms to the disease. It is present when you are suffering from Addison's disease, Hyperthyroidism (Hashimoto's thyroditis), Hypothyroidism, Iron Deficiency, Scarring, Seborrheic Dermatitis, Secondary Syphilis, Systemic Lupus Erythema tosus (SLE), and Vitiligo amongst other diseases.

Types of Hair loss

• Traction alopecia

Traction alopecia is hair loss due to excessive and chronic pulling, or traction, on hair. It commonly occurs in people who braid or knot their hair, but can also be a side effect of pulling the hair during stress. Pronounced traction alopecia is normal in the beard area of this Sikh man, as their religion forbids them to cut any of their body hair. The hair is pulled up tightly in elastic, and is then covered by a turban. “The Kanga” is a band fixed around the chin to make the beard tidy after it has been pulled straight, twisted around and then knotted. In women daily knotting or braiding can cause the hair to break.

• Alopecia areata

Is the development of patches of baldness, normally seen on the head in small circles. It is thought to be a disease of the auto immune system, and the body attacks the hair follicle, usually in the dermal papilla area. It is very common in the South of the Mediterranean basin, especially amongst Greeks, Turks, Spaniards and Italians. Eventually the hair does grow back, but the condition often reoccurs.

A chronic case of alopecia areata leads to alopecia totalis, which is total baldness, but alopecia universalis means that all the bodies’ hair is lost. It is rarely permanent, but it is prone to reoccurrences.

• Telogen Effluvium (Stress Trigger)

When we are subject to stress a traumatic change can take place in the hair follicles. Growing hair follicles are in the anagen growth phase can be catapulted into the catagenic, resting stage. The follicle releases the old dead hair without providing a new one. It is secondary only to androgenetic alopecia as a reason for hair loss. It affects small areas of the scalp, with no pattern.

• Anagen Effluvium (Chemical Damage)

Like Telogen effluvium, this form of hair loss initially causes patchy loss of hair, which then spreads until all the hair is lost. This form of hair loss is more extreme as the hair follicle is not only shut down it is destroyed along with the anagen hair. Chemotherapy the cancer treatment causes this effect. When cancerous cells are present into the body we use medicine to destroy them, at the moment that medicine is not specific, it destroys all cells. Which means that hair follicles are always affected by chemotherapy, though to a greater or lesser extent. Normally hair growth resumes about six months after the cessation of treatment. Other treatments and drugs can cause a similar catastrophic, temporary destruction.

Male and Female Hair Loss Patterns

• Male Hair Loss Pattern

Male baldness is correctly referred to as “androgenetic alopecia”. The “andro” is from the stem androgens, testosterone, and dihydrotestosterone, which have are necessary for the hair loss to occur. Genetic refers to the genes present to allow the condition to happen.

The first sign of this type of baldness in Caucasian males is usually evident around the temple. However hair loss is not predictable, no further signs may develop, or the regression of hair may continue, or it may develop another different lines altogether. Also a receding level of androgens does not slow the process down, if the gene is present, with androgens it will occur.

The process of androgenetic alopecia is increased when there is increase in the male hormone dihydrotestosterone (DHT) within the hair follicle. DHT is a highly active form of testosterone. Testosterone influences aspects of masculine behavior, from aggression to sex drive. Testosterone is converted to DHT by an enzyme called 5-alpha reductase, which is produced in the prostate, the scalp and various adrenal glands. Over a period of time, DHT causes hair follicles to degrade and shortens their anagen, or active, phase.

Beard growth and male pattern hair loss are dependent on dihydrotestosterone (DHT). Testosterone is converted to DHT by the action of enzymes, if this enzyme action is blocked it decreases the amount of DHT. The cells that bind the androgens have receptors, and these receptors have the greatest affinity for DHT followed by testosterone, estrogen, and progesterone. Once the two have bonded together, they enter the cell and interact with the nucleus. This has the effect of changing the production of protein by DNA in the cell, once this has occurred the hair follicle ceases to produce a new hair.

This affects the growth cycle, in the sense that there are fewer hairs in the growth phase, and the growth phase is shortened, this results in the growth of shorter hair. Both these factors means that more hairs are in the resting phase; as there are more hairs, the risk of them being damaged during washing and brushing increases.

Eventually this may spread to a whole area, and the results in the hair on the head being finer and shorter. As the production of hair becomes miniaturized, the pigment also stops being produced. This has the effect of making the hair appear lighter, and also thinner.

These are patterns of hair loss, but to predict an individual prognosis regarding the future loss of hair is impossible. All that can be said with certainty is that once the process of going bald has started it will progress. As the process is genetic you have a greater risk of premature baldness if it runs in the family. However there are many cases in families with two brothers, both in there thirties, one with a receding hairline and one with a full head of hair.

• Female Hair Loss Pattern

In women the process is androgenetic alopecia, it is similar to the male pattern in that it rarely covers the whole head. In women it is rarely hair loss, there are not normally bald patches. Typically it is usually characterized by thinning hair. In women it usually occurs just after the menopause, and is a result of hormonal changes in the body.

It follows the same miniaturization process of the male, the hair gets shorter when it grows and finer, it resembles down and not hair.

In the event of a hormonal imbalance hair loss can occur in women much earlier. Hormonal changes are possible during and after pregnancy, or when the birth control pill is ceased. Stress can be a contributory factor to hair loss or alopecia. In this case the loss is seen in a specific area, it can be temporary or permanent. During the times, when the sufferer is under permanent stress it can be problematic to work out the exact cause of the hair shedding. This is because it normally does not fall out until three or four months later. Once it has fallen out it can take eight or nine months to re-grow. That means that the hair may not be normal again for twelve months.