A sleep study is a non, Invasive, Overnight exam that allows doctors to monitor you while you sleep to see what s happening in your brain and body. For this test, You will go to a sleep lab that is set up for overnight stays usually in a hospital or sleep center. While an eeg, You sleep monitors your sleep stages and the cycles of rem and nonrem or nrem sleep you go through during to identify, The night possible disruptions in the pattern of your sleep. A sleep study will also measure things such as oxygen levels, Eye movements in your blood through a sensor there are no needles involved, Heart and breathing rates, Snoring, And body movements.