Cupping refers to the application of suction cups to the skin. Cups may be made of many materials, and may use fire to create a vacuum (in the case of traditional "fire" cups) or may use a suction device to mechanically remove enough air to create suction. Cups may be left in place or moved around. Typically, the suction causes the skin turns to turn temporarily darker in a painless "hickey", which indicates that blood has been pulled from deeper tissues to the area below the skin; these suction marks may persist for several days to several weeks. 

Cupping is an ancient practice used in many long-standing healing traditions around the world. It is used by acupuncturists as an adjunctive therapy to "move stuck blood", i.e. to promote circulation, remove wastes from chronically tight muscles and joints, and help force fresh nutrients into musculature and tissues. It can assist in the resolution of long-term chronic injuries, to relieve the discomfort of aching muscles, either chronic or acute, and to help speed up the course of colds and flu and relieve associated body aches. Preliminary research supports its use for pain relieving and immune-modulating effects.