The cups can be various shapes including balls or bells, and may range in size from 1 to 3 inches (25 to 76 mm) across the opening. Plastic and glass are the most common materials used today, replacing the horn, pottery, bronze and bamboo cups used in earlier times. The low air pressure required may be created by heating the cup or the air inside it with an open flame or a bath in hot scented oils, then placing it against the skin. As the air inside the cup cools, it contracts and draws the skin slightly inside. More recently, vacuum can be created with a mechanical suction pump acting through a valve located at the top of the cup. Rubber cups are also available that squeeze the air out and adapt to uneven or bony surfaces.
In practice, cups are normally used only on softer tissue that can form a good seal with the edge of the cup. They may be used singly or with many to cover a larger area. Skin may be lubricated, allowing the cup to move across the skin slowly.
Once the suction has occurred, the cups can be gently moved across the skin (often referred to as “gliding cupping). The suction in the cups causes the skin and superficial muscle layer to be lightly drawn into the cup. Cupping is much like the inverse of massage – rather than applying pressure to muscles, it uses gentle pressure to pull them upward. For most patients, this is a particularly relaxing and relieving sensation. Once suctioned, the cups are generally left in place for about ten minutes while the patient relaxes. This is similar to the practice of Tui Na, a traditional Chinese medicine massage technique that targets acupuncture points as well as painful body parts, and is well known to provide relief through pressure.
Depending on the specific treatment, skin marking is common after the cups are removed. This may be a simple red ring that disappears quickly, the discolouration left by the cups is normally from bruising especially if dragging the cups while suctioned from one place to another to break down muscle fiber. Usually treatments are not painful.