Sleep studies or Polysomnograms (PSG) are tests that measure how well you sleep and how your body responds to sleep problems. These tests can help your doctor find out whether you have a sleep disorder and how severe it is.

Sleep studies are important because untreated sleep disorders can raise your risk for heart disease, high blood pressure, stroke and other medical conditions. Sleep disorders also have been linked to an increased risk of injury, such as falling (in the elderly) and car accidents.

You also may want to talk with your doctor if you often have trouble falling or staying asleep, or if you wake up too early and aren't able to go back to sleep. These are common signs of a sleep disorder.