Hair is the second fast growing tissue in the body only after bone marrow. Hair grows about 1 to 1.5 cm every month. On average, the lifespan of a human hair is 2 to 7 years.
Kids lose on average 90 hairs everyday, which rises to 120 by old age. Most people normally shed 50 to 100 hairs a day. This usually does not cause noticeable thinning of scalp hair because new hair is growing at the same time.
The following are some of the common causes of hair loss:
Heredity – It is the most common cause of hair loss and occurs primarily in a predictable pattern such as male pattern or female pattern baldness, which is receding hairline and baldness spots in men and thinning hair in women respectively. Heredity also affects the age at which one one to lose hair, the rate of hair loss and the amount of baldness.
Medical conditions –
- Hormonal changes – Hormonal changes and imbalances can cause temporary hair loss. Women frequently lose more hair two to three months after delivery due to the secretion of more estrogen hormone during pregnancy. Hormone levels are also affected by the thyroid gland, so thyroid problems may cause it.
- Scalp infections – An unhealthy scalp can cause inflammation, resulting in hair fall. Skin conditions that lead to hair loss include seborrheic dermatitis (dandruff), psoriasis, and fungal infections such as ringworm. Once infections are treated, hair generally grows back.
- Alopecia areata – Alopecia areata is an autoimmune disorder in which the immune system attacks hair follicles. It occurs specifically in men and women. The cause is unknown, but it may be triggered by stress or illness.
- Iron deficiency anemia – This is one of important causes especially in those who do not eat iron rich food. Since red blood cells transport oxygen to cells through body, hair follicles are depleted of oxygen in people having anemia.
- Polycystic ovarian syndrome – The condition, which can begin as early as age 11, is caused by a hormonal imbalance in which the ovaries produce too many male hormones.
- Lupus – Lupus is a chronic autoimmune disease in which the body's own immune system attacks healthy tissues including skin along other parts of the body. It can cause hair loss. The condition affects about 1.5 million people and tend to strike women during their childbearing years.
- Lack of protein – If a person is not get enough protein in diet, the body may ration protein by shutting down hair growth. So one should not neglect the adequate intake of this essential macronutrient.
- Sudden weight loss – Sudden weight loss is a form of physical trauma that can result in thinning hair. Loss of hair along with noticeable weight loss may also be a sign of an eating disorder such as anorexia or bulimia.
- Medications – Hair loss can be caused by drugs used for cancer, arthritis, depression, heart problems, high blood pressure and birth control. Intake of too much vitamin A may cause it as well. Chemotherapy destroys rapidly dividing cancer cells but simultaneously it may also destroy rapidly dividing cells like hair.
Other causes –
Over styling – Vigorous styling and hair treatments over the years can cause hair to fall out. As these practices can actually affect the hair root, so hair might not grow back.
Trichotillomania – Trichotillomania is an impulse control disorder, causing people to compulsively pull their hair out. It's sort of like a tic that the person is constantly playing and pulling their hair, which unfortunately can result in hair loss. Trichotillomania often begins before the age of 17 and is four times as common in women as in men. The condition requires specialized treatment.
The bottom line –
Hair loss is one of the commonest problems most of us have and, therefore, we run from pillar to post to find its treatment. Sometimes, we may be able to arrest hair loss if we come across a good expert but, many a time, we fail to control it. The above listed causes will give us a general understanding why hair loss takes place. And this may help us avoid things or medicines that initiate to cause hair loss.