There are several reasons for itching when you sweat: 1, itchy and many bumps when you sweat, after a while these bumps disappear, the symptoms of itching also disappear consider acute urticaria, you can take oral loratadine tablets for treatment, sweat in time to dry the sweat, change clean clothes; 2, the skin is one of the organs of the body to excrete waste, when sweating part of the waste in the body will be discharged, this garbage to the The bacteria on the surface of the skin provide nutrition, so that they breed and multiply in large numbers, so the symptoms of itching will occur. If this condition persists, in addition to the usual lack of attention to personal hygiene, the skin is in a humid environment for a long time, which can lead to local fungal infections forming ringworm, ringworm and many other skin diseases. Paying attention to personal hygiene, choosing cotton, breathable clothes, and keeping the skin clean and dry can effectively inhibit bacterial reproduction and make the symptoms of itchy skin lessen or disappear after sweating.