What are some ways to knock someone unconscious?

There is no way to knock a person unconscious for more than a few minutes without risking severe brain damage or death. Unconsciousness results from a lack of oxygen to the brain, blunt trauma or a drop in blood pressure, according to Healthline.

Severe blunt force trauma to the head can cause internal hemorrhaging, creating fatal pressure on the brain. Should an individual need to induce unconsciousness in self-defense, one method is the triangle choke, which involves compressing the carotid arteries between the upper and lower arm, according to Black Belt magazine. This so-called "blood choke" is a quick method but can be dangerous because it is possible to tear or crush the artery.