What exactly is hair loss?
With the exception of the palms and soles, our eyelids and navels, hair grows everywhere on human skin, yet many hairs are so thin that they are almost undetectable. Hair is composed of keratin, a protein generated in the hair follicles in the outer layer of the skin. As follicles develop new hair cells, old cells are pushed through the skin’s surface at a rate of about 6 inches each year.
The visible hair is a thread of dead keratin cells. The typical adult head contains 100,000 to 150,000 hairs and loses up to 100 each day; a few stray hairs on your brushes are no cause for concern.
About 90% of the hair on a person’s scalp grows at any one time. Each follicle has its life cycle, which is affected by age, disease, and a range of other conditions. There are three stages in this life cycle:
anagen – active hair growth that usually lasts two to eight years.
catagen – two to three weeks of temporary hair growth
Telogen – a rest period lasting approximately two to three months; at the end of the resting phase, the hair is lost, replaced by new hair and the growth cycle begins again.
Hair growth slows as people get older. There are different forms of hair losscommonly known as alopecia:
- Involutional alopecia is a normal condition in which the hair thins over time. More hair follicles rest and the remaining hairs become shorter and fewer in number.
- Alopecia areata is a condition that causes patchy hair loss in children and young adults. This disease can cause complete baldness (alopecia totalis). However, in about 90% of patients with the disease, hair grows back within a few years.
- Alopecia Universalis involves the loss of all body hair, including the eyebrows, eyelashes, and pubic hair.
- Trichotillomania is a psychiatric illness in which a person pulls out their hair. It is especially common in young people.
- Telogen effluvium is a transient hair loss on the scalp caused by changes in the hair development cycle. When a significant number of hairs reach the resting phase at the same time, they fall out and become thinner. Find out what causes telogen effluvium.
- Scarring alopecia causes permanent hair loss. Inflammatory skin problems (cellulitis, folliculitis, acne) and other skin diseases (such as some types of lupus and lichen planus) can cause scarring that hinders hair regeneration. Hot combs, as well as hair that is too tightly braided and twisted, can cause irreversible hair loss.
What factors contribute to hair loss?
- Doctors are baffled as to why certain hair follicles are wired to develop faster than others. However, several variables can cause hair loss:
- Hormones, such as elevated androgen levels (male hormones normally produced by both men and women)
- Genes inherited from both male and female parents can influence a person’s tendency toward male or female pattern baldness.
- Temporary hair loss can be caused by stress, illness or childbirth. Ringworm, which is caused by a fungal infection, can also lead to hair loss. Learn what you can do to reduce stress-related hair loss. Temporary hair loss can be caused by drugs such as chemotherapy treatments used to treat cancer, blood thinners, beta-adrenergic blockers used to control blood pressure, and birth control pills.
- Temporary hair loss can be caused by burns, accidents and X-rays. Unless a scar is formed, normal hair growth normally resumes once the damage has healed. The hair will never regenerate after that.
- Alopecia areata can be caused by an autoimmune disease. The immune system overreacts in alopecia areata for unknown causes, affecting the hair follicles. In most people with alopecia areata, hair will come back, although it can be extremely fine and perhaps a lighter color at first, before returning to its normal shade and thickness.
- Too frequent washing, perming, bleaching and dyeing of hair can all contribute to general hair loss by making hair brittle and brittle. Tight braids, heated curlers and dragging hair sticks through tight curls can all cause hair damage and breakage. However, these operations do not lead to baldness. When the cause of the problem is eliminated, the hair usually grows back on a regular basis. However, significant hair or scalp loss can result in permanent bald patches.
Medical problems. Hair loss can be caused by thyroid disease, lupus, diabetes, iron deficiency anemia, eating disorders and anemia. Unless there is scarring, as in some cases of lupus, lichen planus, or follicular disease, hair will usually grow back when the underlying problem is addressed.
eating pattern. Temporary hair loss can also be caused by a low-protein or extremely calorie-restricted diet. Learn about the foods that can help prevent hair loss.
