Night sweats Sweating is an autonomic response–sympathetic rebound. When you are very tired, then it’s easier to go through theta and into delta at the beginning of sleep. The very fast EEG, however, probably results in waking up when your brain tries to enter REM. The beta that characterizes REM can be too much and too fast and result in waking you up. A sympathetic rebound is what happens when the brain suddenly realizes it has been “too relaxed” and […]