Hair is continually falling out and regrowing in cycles that last several months. However, the discovery of an excessive amount of hair on the pillow, or hair that comes out in clumps during brushing may be cause for concern. The appearance of several small bald patches on the scalp indicates a condition known as alopecia.
Excessive loss of hair can be due to a deficiency in certain minerals and proteins. It is sometimes connected to anaemia, fatigue or to problem with the endocrine glands. It can also be caused by alcoholism or by certain drugs. Well defined patches of complete baldness surrounded by normal hair may be related to other autoimmune conditions, but usually resolves it eventually. Sometimes there is a psychological cause behind hair loss due to habitual pulling out of hair.