Tests and diagnosis

By Mayo Clinic Staff

To diagnose your condition, your doctor may make an evaluation based on your signs and symptoms, an examination, and tests. Your doctor may refer you to a sleep specialist in a sleep center for further evaluation.

You'll have a physical examination, and your doctor will examine the back of your throat, mouth and nose for extra tissue or abnormalities. Your doctor may measure your neck and waist circumference and check your blood pressure.

A sleep specialist may conduct additional evaluations to diagnose your condition, determine the severity of your condition and plan your treatment. The evaluation may involve overnight monitoring of your breathing and other body functions as you sleep. Tests to detect obstructive sleep apnea include:

  • Polysomnography. During this sleep study, you're hooked up to equipment that monitors your heart, lung and brain activity, breathing patterns, arm and leg movements, and blood oxygen levels while you sleep. You may have a full-night study, in which you're monitored all night, or a split-night sleep study.

    In a split-night sleep study, you'll be monitored during the first half of the night. If you're diagnosed with obstructive sleep apnea, staff may wake you and give you continuous positive airway pressure for the second half of the night.

    This test can help your doctor diagnose obstructive sleep apnea and adjust positive airway pressure therapy, if appropriate. This sleep study can also help rule out other sleep disorders, such as periodic limb movements of sleep or narcolepsy, which also can cause excessive daytime sleepiness, but require different treatment.

  • Oximetry. This test monitors and records your blood oxygen level while you're asleep and can be used a screening test for obstructive sleep apnea. If you have obstructive sleep apnea, the results of this test will often show drops in your blood oxygen level during apneas and subsequent rises with awakenings.

    If the study reveals temporary drops in oxygen compatible with obstructive sleep apnea, a polysomnogram may follow to formally diagnose obstructive sleep apnea and determine appropriate therapy.

  • Portable monitoring. Under certain circumstances, your doctor may provide you with an at-home version of polysomnography to diagnose obstructive sleep apnea. This test usually involves measurement of airflow, breathing patterns and blood oxygen levels.

Your doctor also may refer you to an ear, nose and throat doctor to rule out any anatomic blockage in your nose or throat.

Jun. 15, 2013