Hair loss is a condition when the hair follicles produce new hair cells, older hair cells are pushed out through the surface of the skin at a speed of about 15 centimeters per year. Hair grows everywhere on human skin except on the palms and soles of our feet, but many hairs are so smooth that they are almost invisible. Hair consists of a protein called keratin which is produced in hair follicles in the outer layer of the skin. The hair we can see is actually dead keratin cells. The average adult's head has around 100 thousand to 150 thousand hairs and loses up to 100 hairs a day; finding some combed hair is not necessarily a health disorder.
At one time, about 90 percent of the hair on a person's scalp grows. Each follicle has its own life cycle that can be affected by age, disease, and various other factors. This hair life cycle is divided into three stages:
- Anagen - active hair growth that lasts between two and six years
- Katagen - transition hair growth that lasts for two to three weeks
- Telogen - a resting phase that lasts about two to three months; at the end of the resting phase the hair is lost and new hair will replace it, and the growth cycle begins again.
As we age, the hair growth rate slows down.
Causes of Hair Loss
There are many types of hair loss, which are also called alopecia:
- Involutional alopecia is a natural condition in which hair gradually thinns with age. More hair follicles enter the resting phase, and the remaining hair becomes shorter and fewer in number.
- Androgen alopecia is a genetic condition that can affect both men and women. Men with this condition, called male pattern baldness, can begin to suffer from hair loss from an early age (adolescence) or early 20s. This is indicated by the hairline that grows on the forehead, which progressively retreats backward and the loss of hair gradually from the forehead area. Women with this condition, called female pattern baldness, do not experience thinning seen until their 40s or more. Women experiencing thinning hair usually occur evenly throughout the scalp, with the most loss on the forehead.
- Alopesia areata often starts suddenly and causes hair loss in children and young adults, as often as the lay is called "pitak". This condition can cause complete baldness (alopecia totalis). But in about 90 percent of people with this condition, hair will grow back in a few years.
- Alopesia universalis causes all body hair to fall out, including eyebrows, eyelashes and pubic hair.
- Trichotillomania, seen most often in children, is a psychological disorder in which a person pulls his own hair.
- Telogen effluvium is thinning hair on the scalp that occurs due to changes in the hair growth cycle, is temporary. A large amount of hair enters the resting phase at the same time, causing subsequent hair loss and thinning.
- Alopecia scarring results in permanent loss of hair. inflammatory skin conditions (cellulitis, folliculitis, zits), and other skin disorders (such as some forms of lupus and lichen planus) often cause injuries that destroy the hair's ability to regenerate. Combing too hard and hair tied and pulled too tight can also cause permanent hair loss.
Other Causes of Hair Loss
Several factors can affect hair loss:
- Hormones, like normal androgen levels (male hormones are usually produced by men and women)
- Genes, from parents both from mother and father, can influence a person's tendency to get male pattern baldness or female pattern baldness.
- Stress, illness, and childbirth can cause temporary loss. Ringworm ringworm on the scalp caused by fungal infections can also cause hair loss.
- Medicines, including chemotherapy drugs used in cancer treatment, blood thinners, beta-adrenergic drugs used to control blood pressure, and birth control pills, can cause temporary hair loss.
- Burns, injuries, and X-rays can cause temporary hair loss. In such cases, normal hair growth usually returns after healing an injury unless there is scarring.
- Autoimmune diseases can cause alopecia areata. In alopecia areata, the immune system goes down for reasons that are unknown and affect hair follicles. In most people with alopecia areata, hair grows back, although there may be some that grow very well and maybe there are those who get a lighter color than before
- Cosmetic procedures, such as shampooing too often, bleaching, and coloring hair can contribute to overall thinning of the hair by making hair weak and brittle. Straining hair tightly, using rollers or hot patches, with hair medicines can also damage and break hair. However, this procedure does not cause baldness. In most cases the hair grows back to normal if the source of the problem is overcome. However, severe damage to the hair or scalp sometimes causes permanent baldness.
- Medical condition. Thyroid disease, lupus, diabetes, iron deficiency, eating disorders, and anemia can cause hair loss. Often, when the underlying condition is treated, the hair will return unless there is scarring as in some cases of disease namely lupus, lichen planus or follicular disorders.
- A low-protein diet or a severe calorie-limited diet can also cause temporary hair loss.