A sleep study is done at a sleep clinic. Sensors will be placed on your head and body to record your brain waves, breathing, and body movement. A small monitor that clips onto your finger will also be used to keep track of blood oxygen levels. Your sleep will be watched all night in a study called a polysomnogram. You will also have a daytime nap study called a multiple sleep latency test. The results will help your provider diagnose narcolepsy. Then your treatment can be planned.