A sleep evaluation, also known as polysomnography or a sleep study, is used to diagnose sleep disorders or determine a treatment plan. During a sleep study, you'll sleep while your brain waves, oxygen level, heart rate, and breathing are measured.
Sleep studies can also be used to look at how another condition, such as epilepsy, affects your sleep.
Many sleep studies are done in a sleep lab, but they can be done at home in some cases.