Sveda Vidhi or svedana means the elimination of poison from the body through sweat (sveda). Svedan, or the act of sweating, relieves the body from stiffness, heaviness and cold. Svedan or sveda-vidhi (method of perspiration) is the first act (purvakarma) in panchakarma (the five methods of cure). Svedan is done after oiling (snehan).
Svedavidhi is categorized in Ayurveda as an antidote to the excess of two factors (doshas), vata (air) and kapha (mucus). Svedan is always prohibited in bile-related (pittaja) diseases.
In the winter season, mahan svedan (tough sweat) is done, and in the summer season, mridu svedan (soft sweating) is advised. The scrotum, heart and eyes should be prevented from sveda. During sveda vidhi these organs should be covered by lotus leaves or dough.
Acharya Sushruta describes four types of sveda – tap sveda, unah sveda, ushna sveda and drava sveda.
In case of excessive sweating, there may be a burning sensation in the body, general weakness in the body, pain in the joints, reddish-black patches on the skin, thirst, fever, and vomiting. Then sweet, cool, smooth and light food should be given. Alcoholic drink is prohibited. Salty, acidic, bitter and hot food items should not be eaten; a face pack of sandalwood should be applied.
Just after sveda vidhi, the person should not come in contact with open air and cold water. The sweat should be wiped off by thorough sponging with hot water. After giving some rest to the patient, he should be given a bath of hot water, liquid and light food, and then allowed to sleep.
After svedan, purgatory methods like vaman (vomit) and virecan (purgation) can be administered on the second and fourth days.