Cupping Therapy, is a simple technique that applies suction to the skin; it quickly releases muscle tension to relieve pain; it loosens and lifts connective tissues, breaks up fascial adhesions from old injuries or overworked muscles, and increases blood and lymph to skin, muscles, and connective tissues.
Often times, when pain is present, it is due to blockage of blood flow to the affected area. Cupping effectively brings stagnant blood and cellular waste to the surface, so that it can all be flushed out by the liver and kidneys. This allows fresh, oxygenated blood, cells, and nutrients to flow freely to the targeted areas in order to facilitate healing.
So no it does not hurt, but actually provides much appreciated pain relief!