A diagnosis of sleep apnea can be difficult to confirm, because there's no blood test or urine test for it like there is for many other conditions and diseases. It only happens during sleep, so it probably won't be detected during a routine physical exam. Obtaining a diagnosis of sleep apnea, a condition in which sufferers stop breathing for as long as a minute during sleep, requires analysis of several factors, including the patient's medical history, a physical exam and perhaps an overnight stay at a sleep center.
The doctor starts by asking the patient and his or her family about sleeping habits, including how often the patient snores or makes gasping or choking sounds during sleep. The doctor might also ask the patient to keep a sleep diary, which tracks the patient's sleep habits and level of drowsiness during the day. The doctor will also want to know if anyone in the patient's family has been diagnosed with a sleep disorder.
As part of the physical exam, the doctor will examine the patient's mouth, throat and nose to look for extra or large tissues. In children, the doctor might also look for enlarged tonsils. In adults, the doctor might look for an enlarged uvula, which is the tissue that dangles from the top of the back of the mouth. The doctor also might check for enlarged soft palate, which runs along the roof of the mouth in the back of the throat.
The most precise way to obtain a diagnosis of sleep apnea is through a sleep study, which can be conducted by the patient in his or her own home or at a sleep center or sleep lab. The most common kind of sleep study is a polysomnogram (PSG), which uses sensors placed on the chest, face, scalp, limbs and finger. While the patient sleeps, these sensors measure things such as breathing, blood pressure, brain activity, eye movement, the amount of air that moves in and out of the lungs and the amount of oxygen in the blood.
Doctors sometimes perform a split-night sleep study, which uses a piece of sleep apnea equipment called a continuous positive airway pressure machine (CPAP). A CPAP, which keeps the airways open using air pressure, is the most common treatment for sleep apnea. During a split-night sleep study, the patient's sleep is checked without the use of CPAP to help confirm a diagnosis of sleep apnea. If sleep apnea is confirmed, the doctor will use a CPAP on the patient during the second half of the study, in order to determine the proper settings for the CPAP machine.
Alternatively, the doctor may have the patient use a portable home monitor, a sleep apnea device that measures much of the same information as a PSG. The doctor might use the results from the home study either to confirm a suspected diagnosis of sleep apnea or to determine whether to perform a PSG to further confirm the diagnosis. The patient would use this device in his or her own home, in much the same way that a sleep study is conducted in a lab.