Breath control is the restriction of oxygen for the purpose of heightened sexual arousal and intensified orgasm. Methods of breath control include strangulation, suffocation, and smothering. This practice may be used during consensual sex or masturbation. It is particularly popular in the BDSM community where it is not uncommon for dominants to control their submissives' breathing.
Breath control is also known as erotic asphyxiation or, when it's used on oneself, auto-erotic asphyxiation.
More About Breath Control
Orgasms are said to be much more intense when the brain is deprived of oxygen, but this practice can also be dangerous and even deadly. Individuals and couples looking to experiment with breath play should be extremely cautious. Couples should use communication during the act and employ the use of safe words and gestures. Never use belts, collars, ropes, cords, hanging, or extreme pressure to cut off the oxygen supply. Auto-erotic asphyxiation is particularly dangerous. One estimate from the FBI claims that between 500 and 1,000 people in the U.S. (largely men) die as a result of this practice each year.