"Hair Loss" can be from mild hair thinning to total baldness. These can occur for many different reasons. Medically, hair loss falls into several categories. It may include:
- Telogen effluvium - This form of hair loss happens 2 to 3 months after your body has been under stress. It could include such things as prolonged illness, major surgery or serious infections. This can also occur after a sudden change in hormone levels, like women after childbirth. You would notice moderate amounts of hair fall out from all parts of the scalp, and may be noticed on a pillow, in the tub or on a hairbrush. Your hair on some parts of the scalp may appear thinned but you rarely see large bald spots.
- Traumatic alopecia -This form of hair loss is caused by hairdresser's techniques. It could involve:
In addition, some people have an uncommon psychiatric disorder. This is where compulsive hair pulling and twisting occurs and as a result the scalp will appear bald spots.
- pulling of the hair (tight braiding or corn-rowing);
- exposure of the hair in extreme heat and twisting (curling iron or hot rollers); or
- damages to the hair with strong chemicals (bleaching, hair coloring, and permanent waves).
- Tinea capitis (fungal infection of the scalp) - This is where patches of hair loss occurs on the scalp. It is caused by a certain types of fungus that infects the scalp. This causes the hair to break off at the scalp surface and the scalp to flake or become scaly. Tinea capitis is a common form of patchy hair loss in children.
- Symptom of a medical illness - Symptoms of medical illness can also cause hair loss. These may include lupus erythematosus, syphilis, a thyroid disorder (hair loss occurs in both hypothyroidism and hyperthyroidism), sex-hormone imbalance, or a serious nutritional problem, especially a deficiency of protein, iron, zinc or biotin. These deficiencies are most common in people on restrictive diets or in women who have very heavy menstrual flow.
- Effects of Drugs - Side effect of some medication can cause hair loss. In addition, many medications used in cancer chemotherapy commonly cause sudden hair loss affecting the entire head.
- Alopecia areata - This is a disease that causes hair to fall out in one or more small patches. The cause of this condition is unknown. It is usually common among people who have other autoimmune diseases.
- Hereditary pattern baldness, or androgenetic alopecia - This is the most common form of hair loss among men. It mostly appears in the front hairline, and/or thinning hair at the top of the head. This form of hair loss can begin at any time in a man's life, even during his teen years.
It usually is caused by the interaction of three factors:
- an inherited tendency toward baldness
- male hormones and
- increasing of age.
Some women might development a mild degree of female-pattern baldness. Usually, thinning occurs over the whole top or crown of the scalp, sparing the front of the scalp, so that the frontal receding hairline seen in men does not occur.