Rapid eye movemnt (REM) sleep is a stage of sleep that is characterized by rapid eye movements, low muscle tone throughout the body, and vivid dreams. REM sleep typically occurs ninety minutes after falling asleep, and each period of REM sleep becomes longer with each sleep cycle. During this stage, breathing rate increases, thermoregulation fluctuates, and the body temporarily loses muscle tone. Experts conclude that depriving someone of REM sleep has positive effects, such as the alleviation of depression and aggressive behavior. However, some negative effects include mild disturbances, irritability, anxiety, hallucinations, and a lack of concentration. Therefore, it is recommended that people get enough REM sleep for better health.