As a respiratory physiologist, I can provide insights into the effects of oxygen deprivation on the human body. When a person stops breathing, the body is deprived of the oxygen it needs to function properly. Oxygen is essential for the production of adenosine triphosphate (ATP), which is the primary energy source for cells. Without oxygen, cells cannot produce ATP, leading to a rapid decline in bodily functions. The time it takes for a person to die without breathing can vary greatly depending on several factors, including the individual's health, age, level of physical fitness, and environmental conditions. However, as a general guideline: - Unconscious individuals who are not breathing can survive for about five to ten minutes before irreversible brain damage begins to occur. This is because the brain is particularly sensitive to oxygen deprivation, and neurons start to die off rapidly once the oxygen supply is cut off. - In cases where the body is exposed to cold temperatures, the metabolic rate slows down, and the individual can survive longer without oxygen. This is because a slower metabolism means the body's cells require less oxygen to function. - Younger individuals, particularly infants and children, have a higher tolerance for oxygen deprivation due to their higher concentrations of myoglobin in the muscles, which can bind to oxygen and release it when needed. It's important to note that while the brain can suffer irreversible damage after a certain period without oxygen, the exact time frame can vary, and survival beyond the typical limits has been documented in extreme cases. read more >>

Originally Answered: How long human can survive without oxygen? After five to ten minutes of not breathing, you are likely to develop serious and possibly irreversible brain damage. The one exception is when a younger person stops breathing and also becomes very cold at the same time.read more >>