Hair and hairstyles have always been of great social and cultural importance. A receding hairline or thinning hair has become a very significant problem for both men and women. However, some diseases and unsuitable hair care products can cause hair loss.
Hair loss is common: two out of every three men experience some degree of hair loss. A very high proportion of men and women may also experience different types of hair loss during their lives. With a correct diagnosis, it is possible to help many people with hair loss. When the hair starts to thin, falls out excessively or bald patches appear on the scalp, a dermatologist should be consulted.
Normal Hair Growth
90% of the hairs on the scalp are constantly growing. The growth phase ends after 2 to 6 years. The remaining 10% of hairs are in the resting phase, which lasts about 2–3 months. At the end of this resting phase the hair falls out. Shedding 50–100 hairs a day is considered normal. When a hair falls out, production of a new hair begins from the same hair follicle, starting a new growth phase. Scalp hair grows at about 2–2.5 cm a month. The growth rate slows with age. Short hair also grows faster than long hair. In natural blondes the number of hairs on the scalp is 120,000, whereas in brunettes
The hair growth and development cycle includes 3 phases:
1. Growth phase: About 90% of the hairs on a person’s scalp are in the growth phase. This period lasts about 2–6 years.
2. Resting phase: The period following the growth phase. It lasts about 2–3 months.
3. Shedding phase: Hairs that have completed the resting phase detach from their roots and fall out. New hair growth starts from the root of the shed hair, and so the cycle begins again.
Why Does Hair Loss Occur?
There can be many different causes of excessive hair loss. People who notice excessive hair loss or thinning of their hair should see a dermatologist. It is important to identify the cause and whether it will respond to medical treatment.
* Use of unsuitable hair care products: Products applied to the scalp such as hair dye, bleach, permanent waves and hair strengtheners can damage the hair. If these products are used often, left on the hair for a long time or several are applied at the same time, they weaken the hair and make it break easily.
*Hairstyles can cause hair loss. Tying the hair back tightly and wearing ponytails increase hair loss.
* Frequent shampooing and combing or brushing the hair without conditioner also make the hair break and fall out easily. After shampooing, conditioner should be applied so that the hair can be combed easily.
* Genetic factors cause hair loss.
* Febrile illnesses, thyroid diseases, iron deficiency, strict diets, cancer medicines and tuberculosis medicines cause hair loss.
* Hair loss is seen in mothers after giving birth. Shedding occurs because of changes in the hair cycle due to hormonal changes.
* Psychological factors and stress are among the most important causes of hair loss.
- Patchy hair loss (alopecia areata) is more common in children. Most often, complete hair loss occurs in a limited area of the scalp. Sometimes all body hair may also be lost. The cause of the disease is not fully known. Stress and some psychological problems can trigger it. The hair can regrow with treatment. In rare cases the hair loss can be permanent.
* About 3–4 weeks after an illness with high fever, a large number of hairs may suddenly fall out. However, this shedding usually returns to normal without any intervention.
* Both overactivity and underactivity of the thyroid gland can cause hair loss. Hair loss due to thyroid disease can be reversed with appropriate treatment.
* When insufficient protein is taken in because of an unbalanced diet, the body first shifts hairs from the growth phase to the resting phase in order to conserve protein. In such a situation excessive hair loss usually occurs 2–3 months later. When the hairs are pulled, they come out easily with their roots. This type of hair loss returns to normal once adequate protein is taken in the diet and maintained.
* Some medicines used in cancer treatment cause cell division in the hair cells to stop. The hairs become thin and brittle. This happens 2–3 weeks after treatment. The patient loses more than 90% of their hair. The hair starts to grow again after the treatment is stopped.
* People whose hair thins while taking the contraceptive pill will have a hereditary predisposition to hair thinning. If thinning of the hair is observed due to use of the contraceptive pill, it is advisable to see a gynaecologist and change the pill.
* Iron deficiency can cause hair loss. This involves insufficient iron intake or insufficient iron absorption, for example due to certain diets.
Most hair loss is due to the normal hair cycle. Hair grows about 2.5–3 cm a month. The growth rate decreases with age. Shedding 50–100 hairs a day is normal. If you notice more shedding than this and thinning of your hair, consult a dermatologist.