Death comes in many guises, but one way or another it is usually a lack of oxygen to the brain that delivers the coup de grâce. Whether as a result of a heart attack, drowning or suffocation, for example, people ultimately die because their neurons are deprived of oxygen, leading to cessation of electrical activity in the brain - the modern definition of biological death.
If the flow of freshly oxygenated blood to the brain is stopped, through whatever mechanism, people tend to have about 10 seconds before losing consciousness. They may take many more minutes to die, though, with the exact mode of death affecting the subtleties of the final experience. If you can take the grisly details, read on for a brief guide to the many and varied ways death can suddenly strike.
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