Itchy when you sweat, may be caused by the stimulation of sweat, acute urticaria, dermatophytosis and other factors. Need to according to the specific cause of the symptomatic treatment, usually recommended to pay attention to personal hygiene, if necessary, oral antihistamine, antifungal, glucocorticoid drugs, can help relieve the symptoms. 1. Stimulation of sweat: the skin is one of the organs of the human body that excrete wastes, and some of the wastes can be discharged through sweating. The waste inside the sweat can provide nutrients to the bacteria on the surface of the skin, leading to a large number of bacteria reproduction, which can cause itching. It is recommended to wash in time after sweating and choose cotton breathable clothing, which can effectively inhibit bacterial reproduction and help reduce itching. 2. Acute urticaria: Itchy skin or red spots and pimples after sweating can also be considered to be related to acute urticaria. It is recommended to dry the skin of sweat in time, change clean clothes, and take oral levocetirizine, loratadine and ipratropium if necessary, which can help relieve the symptoms. 3. Dermatophytosis: Dermatophytosis is caused by fungal infection, resulting in localized inflammatory reaction. The stimulation of inflammation can cause itching. Topical ketoconazole, miconazole nitrate, if necessary with oral itraconazole, terbinafine hydrochloride and other drugs, can inhibit or kill the fungus. It is recommended to pay attention to personal hygiene, wash or towel dry after sweating, and go to the hospital dermatology department if necessary to find out whether it is related to disease factors. The above drugs need to be used in accordance with medical advice.