What happens when you don't sleep for three days?

Sleep deprivation causes serious changes in body physiology and mental composure; lack of it may result in irritability, vision impairment, stuttering speech, momentary loss of reasoning, confusions, hallucination and nausea. A consistent lack of sleep may result in a condition known as fatal familial insomnia and chronic dementia, and also leads to people becoming overweight and obese, and such physical transformation will eventually lead to other medical risks and complicated problems.