There are various reasons that lead to cold sweat on the right leg when sleeping at night, such as too thick blanket on the right leg, deep vein thrombosis of the lower extremity, autonomic dysfunction and so on. 1. Right leg quilt is too thick: when the quilt covering the right leg is very thick at night and the left leg covers less, it will make the skin temperature of the right leg higher, and the right leg will discharge heat in the form of sweating to reduce the skin temperature. As a result, sweating of the right leg occurs during sleep. 2. Deep vein thrombosis of the right lower limb: when venous thrombosis occurs in the right lower limb, it will lead to the obstacle of blood circulation in the right leg and reduce the blood supply, which will lead to the situation of cold sweating of the right leg when sleeping. 3. Autonomic dysfunction: autonomic dysfunction of the human body may cause sympathetic nerve dysfunction and cause right leg sweating during sleep. If you are experiencing right leg sweating at night, it is recommended that you go to a regular hospital in time to find out the cause of the problem.