Easy to grow ash on the body is usually caused by excessive sweating, sebaceous glands secretion and other reasons. Body long gray generally refers to the skin shedding of the stratum corneum, as well as the skin secretion of some sweat, external dust and other mixed. If you usually exercise more, sweat more, easy to appear on the body long gray phenomenon. If the sebaceous gland secretion is more vigorous, such as in adolescence, will also appear on the body easy to rub mud, long gray phenomenon. These are generally not to worry about. Usually pay attention to keep the skin dry and clean, shower and change clothes often. If there is excessive sweating or abnormal sebaceous gland secretion, you should go to the hospital in time for appropriate examination.