Cupping is an ancient technique in which glass cups are placed on large areas of the body (such as the back or shoulders) to create suction, increasing local circulation of blood and Qi. Cupping is excellent for detoxification, reducing inflammation, muscle pain and arthritis. It also treats fevers, the common cold, flu, and asthma. A vacuum is created by either using heat or suction, and they then may be moved or left in place. Sometimes dark red marks are left afterwards, showing the deep stagnation that has been released.