Breath control

Breath control (also called breath play) is the intentional restriction of breathing for sexual gratification. When performed specifically to restrict oxygen to the brain, this is called erotic asphyxiation (or when performed alone, autoerotic asphyxiation). Breath control is a high-risk kink and the most common cause of fatalities in solo-play scenes [citation needed].

Background

Humans must breathe to survive. Breathing serves two essential purposes:

• Deliver oxygen to the body
• Remove carbon dioxide from the body

Dysfunction of either can rapidly cause serious injury or death.

Respiratory physiology

Human lungs exchange oxygen for carbon dioxide and store additional oxygen, which allows for brief periods of apnea (pauses in breathing) without harm. The amount of gas stored in the lungs at a given time is described by "lung volumes", and varies depending on what the person is doing. If breathing is paused, adequate oxygenation will be provided to the body until the remaining oxygen stored in the lungs is consumed, after which the person's oxygen saturation will rapidly decrease followed shortly by loss of consciousness.

This table demonstrates how much gas remains in the lungs and how long that gas can supply enough oxygen to the body for a number of different circumstances for an average adult. Note that while the average volumes of gas vary greatly between individuals based upon their lean body weight, there is a reciprocal change in the rate of oxygen consumption meaning that the calculated times until desaturation occurs remain roughly the same.

Amount of gas stored in the lungs

	Normal breathing	Inhaling the largest breath possible	Exhaling as much gas as possible
Terminology	Functional residual capacity (FRC)	Total lung capacity (TLC)	Residual volume (RV)
Volume of gas	2 liters	5 liters	1 liter
Volume of oxygen (if breathing room air)	420 milliliters	1,050 milliliters	210 milliliters
When resting calmly
Rate of oxygen consumption	280 milliliters per minute
Time until oxygen is depleted	90 seconds	3 minutes, 45 seconds	45 seconds
During vigorous sexual activity
Rate of oxygen consumption	1,600 milliliters per minute
Time until oxygen is depleted	15 seconds	1 minute	<10 seconds

Hypoxia (Low oxygen)

Hypoxia is the term used to describe inadequate oxygen delivery to the body. When oxygen is completely depleted:

• Consciousness is lost within seconds
• Permanent brain damage occurs within minutes
• Death is all but certain after 10 minutes

When only breathing is restricted, the amount of time until oxygen is depleted is largely determined by how much oxygen remains in the lungs and the rate at which the body is using oxygen (see table above). However, in certain forms of breath play, such as carotid compression, oxygen is completely restricted from the brain immediately.

Loss of consciousness

Examples of decorticate and decerebrate posturing.

File:Posturing.mp4 When consciousness is lost due to hypoxia, the brain no longer communicates with the body normally and the body enters a reflexive state called posturing. Posturing results in the extreme tension of specific groups of muscles depending on which parts of the brain are denied oxygen. However, in almost all circumstances, the fingers are tightly closed into a fist. This has several extremely important implications:

• It is highly likely that a person will not let go of something they are holding when they lose consciousness
  • Depending on releasing an object in order to restore normal airflow is NOT a safe risk-mitigation strategy
• To people unfamiliar with the appearance of posturing, it may not be apparent that loss of consciousness has occurred