How you prepare

You may be advised to avoid drinks or food containing alcohol or caffeine during the afternoon and evening before polysomnography. Alcohol and caffeine can change your sleep patterns, and they may make symptoms of some sleep disorders worse.

Napping in the afternoon before a sleep study is discouraged. You may be asked to bathe or shower before your sleep study. But don't put on lotions, gels, colognes or makeup before the test, as these can interfere with the use of the electrodes.

For a home sleep apnea test, the equipment is delivered to you or you can pick up the equipment at your doctor's office. You'll be given instructions describing how to use the equipment. Ask questions if you're unsure about how the test or equipment works.