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.
| 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 | |||
| * Metabolic rate | |||
| * Time until oxygen is depleted | 90 seconds | 3 minutes, 45 seconds | 45 seconds |
| During sexual activity | |||
| Metabolic rate | |||
| Time until oxygen is depleted | |||
Hypoxia (Low oxygen)
When oxygen is completely restricted to the brain (e.g. when both carotid arteries are occluded or all oxygen stored in the lungs is depleted):
- Consciousness is lost within seconds
- Permanent brain damage occurs within minutes
- Death is all but certain after 10 minutes