If you have the most classic symptoms of narcolepsy, such as involuntary sleep attacks and weakness attacks (cataplexy), diagnosis of your disorder may be relatively simple. If your doctor isn’t sure whether your symptoms are caused by narcolepsy, she may order tests, such as:

  • Polysomnogram tests—For this test, you’ll have to spend the night in a sleep center. Tiny electrodes will be attached to various areas of your body in order to closely monitor your heart rate, eye movements, brain waves, and muscle activity throughout the night. Monitors will also record information about your breathing, changes in the concentration of oxygen in your blood, and your body position.
  • Multiple sleep latency test—This test is usually done the day after the polysomnogram. With the same set of electrodes still attached, you’ll be asked to take a series of 20-minute naps, every 2 hours throughout the day. The electrodes collect information about how quickly you fall asleep and how quickly you reach various levels of sleep—particularly rapid eye movement (REM) sleep.
  • Genetic blood tests—Narcolepsy is linked to a particular antigen, a substance that triggers your body to make antibodies. Your doctor may test your blood to discover if you have this antigen.