Hair loss, as the name itself implies, refers to the falling of hair from scalp / head; another term used to describe this is alopecia. It is a broad term that also includes thinning of hair. While genetics plays a vital role in this condition that afflicts both men and women, there are several other factors that are involved in bringing on this problem in people. In order to understand the reasons for hair fall better, it is essential that you learn about the various growth stages of hair. The hair growth cycle consists of three phases:
After completion of last stage, the entire cycle is repeated. Each single hair undergoes these three phases of growth independent of the other hair on the scalp. Normally, at a given point of time about 90% of hair is in the anagen phase and only 10% is in the telogen phase. When this ratio is altered, it leads to increased rate of hair loss. Hair loss can occur at any age, and can be prevalent in both males and females. Hair loss in itself is not a disease, but a sign that often indicates various other diseases. Hair loss occurs as a result of various diseases or factors and in different patterns.
The various causes / factors leading to hair loss include:
1) Skin diseases affecting the scalp like fungal infection of scalp known as tinea capitis, seborrhoea (dandruff), eczema of scalp, or lichen planus.
2) Genetic factors.
3) Hormonal changes including those that occur after childbirth and during menopause.
4) Nutritional deficiencies due to a diet that lacks iron (leading to anemia), and also lack of protein intake.
5) Recovery from acute fever like typhoid and erysipelas leads to diffuse hair loss.
6) Drug use like the ones that are used in treating high blood pressure, joint pains, cancer, or depression. Anagen effluvium refers to the condition of hair loss due to chemotherapy in a cancer patient.
7) Physical trauma / injury to head.
8) Emotional trauma like constant stress or grief due to loss of a family member / close friend.
9) General diseases like diabetes mellitus, tuberculosis, Hypothyroidism, or AIDS.
10) Auto-immune related hair loss in which the hair cells are mistaken for a foreign body and are destroyed by the immune cells of the body.
11) Hairstyles like tight braids or ponytails where the hair is tightly pulled backwards leading to traction alopecia; indiscriminate use of hair colors and hair straighteners.
12) Trichotillomania, which is a mental disorder in which the affected person voluntarily pulls out his / her scalp hair.