Itchy skin after sweating may be caused by cholinergic urticaria, skin sensitization and so on. 1. Cholinergic urticaria: a special type of urticaria, mostly seen in young patients, mainly due to various reasons, such as heat, exercise, emotional stress, eating hot drinks, etc., so that the temperature of the body rises, cholinergic nerves release acetylcholine, the role of mast cells and the onset of the disease. The main manifestation of urticaria is the appearance of 1~3mm in diameter papular windsock a few minutes after stimulation, conscious itching, stinging or burning sensation, sometimes only severe itching without skin lesions, can be subsided in 30-60 minutes, is one of the causes of itchy skin after sweating. 2. Skin sensitivity: sweat contains many ingredients, such as salt, urea, lactic acid, fatty acids, etc., the more sensitive skin people may be stimulated by these substances, itching symptoms, which can cause itchy skin after sweating. There are many other causes of itchy skin after sweating, which should be taken seriously, and timely consultation should be made to identify the cause of the disease and follow the medical advice for further treatment or therapy.