During cupping, a silicone, glass, or plastic cup is placed on the skin and the practitioner removes the air inside the cup using suction, a pump, or a flame. The lack of air inside the cup causes skin and connective tissue to get pulled up into the cup. This technique is used to release stuck tissues or pathogens which can cause pain and illness. The technique should be painless, and feels like a strong massage. The cups may be left in place or slid across lubricated skin, depending on the desired outcome. Cupping causes red and purple spots under the surface of the skin. This is a normal and expected outcome of cupping, and should resolve within a week or two.