Losing hair is a natural part of the body’s renewal process. As hair falls out, new growth replaces it. Most people suffer from excessive hair loss at some time in their life. There are a number of factors for this including medication, radiation, chemotherapy, exposure to chemicals, hormonal and nutritional factors, thyroid disease, generalized or local skin disease, and stress. Many of these causes are temporary and a few are permanent.
Some of the factors which cause hair fall are lifespan, styling, and aging. The average lifespan of a single hair is 4.5 years; the hair then falls out and is replaced in a few months by new ones. Shampooing, blow drying, and brushing hair can all cause hair to fall out. After the age of 30, men and women both start losing hair, though men tend to do so at a faster rate.
Many of us have heard that stress can cause hair loss, and that’s true. Excessive physical or emotional stress, which is associated with injury, illness or surgery, can cause two types of hair loss such as telogen effluvium which is a less severe type of hair loss. The hair stops growing and lies dormant. It falls out 2 or 3 months later and grows back within 6 to 9 months.
The other type of stress-induced hair loss is alopecia areata, which involves a white blood cell attack on the hair follicles. With this type of hair loss, the hair falls out within weeks of the attack, usually in patches, but can involve the entire scalp and even body hair. Hair may grow own its own, but treatment may also be required.
Hormonal problems may also cause hair loss. If the thyroid gland is overactive or underactive, hair may fall out. Hair loss may occur if male or female hormones are out of balance. Correcting the hormone imbalance may stop your hair loss. During pregnancy, high levels of certain hormones cause the body to retain hair that would normally fall out. When the hormones return to pre-pregnancy levels, that hair falls out and the normal cycle of growth and loss starts again.
Some medicines can cause hair loss. This type of hair loss improves when you stop taking the medicine. Medicines that can cause hair loss include blood thinners (also called anticoagulants), medicines used for gout, high blood pressure or heart problems, oral contraceptives and antidepressants, seizure medication, anti-inflammatory drugs, mood altering drugs, chemotherapy and diet pills, high doses of Vitamin A.
Nutritional deficiencies can also cause hair loss. Some conditions that can trigger hair loss due to deficiencies are anorexia nervosa, protein/calorie deficiency, essential fatty acid or zinc deficiency, malabsorption, and iron deficiency anemia.
Certain infections such as a fungal infection or an underlying disease such as lupus or diabetes can give rise to hair fall. Since hair loss may be an early sign of a disease, it is important to find out the cause, and treat it so that the hair loss stops on its own.