In the cupping process, a partial vacuum is created by suction or heating special glass “cups.” When heated, a vacuum is formed inside them, and the rim of the cup is held gently against the skin. There is no chance the skin will be burned. More than one cup is usually applied. A bruise may form where cups are placed, but this is not painful and the bruise heals quickly. The bruise is not from blunt trauma like a typical bruise but from the suction pulling blood that is stuck in the tissues to the surface so that new blood flow can come to the traumatized area and heal the underlying tissues (like a hickey – but no necking involved).
Cupping has become more well known because so many olympians such as Michael Phelps have utilized it to help their recovery times during intense training.