The symptoms of obstructive sleep apnea are not very specific. This means that most people who snore at night or who feel tired during the day probably do not have sleep apnea. Other medical reasons for daytime sleepiness should be considered by your doctor before referral to a sleep center for diagnostic sleep tests. They include:
- Having to work excessive hours or varying shifts (nights, weekends)
- Medications (tranquilizers, sleeping pills, antihistamines beta blockers, many others)
- Alcohol abuse
- Medical conditions (such as hypothyroidism, hypercalcemia, and hyponatremia/hypernatremia)
- Self-imposed short sleep time
- Other sleep disorders, such as narcolepsy, insomnia, or restless legs syndrome
- Chronic fatigue syndrome
- Depression or dysthymia
Symptoms or findings that make the need for evaluation by a sleep specialist include:
- Sleepiness is affecting patient's quality of life
- Sleepiness on-the-job places the patient or others in danger
- Others have observed apnea or breath-holding episodes while asleep
- Other medical illnesses that may be worsened by obstructive sleep apnea are present.
- Children who are snoring a lot and are irritable, not thriving or growing well, or having behavioral issues
If symptoms suggest obstructive sleep apnea or other sleep disorders, further diagnostic testing will be performed. A sleep specialist or sleep disorders center will perform an in-depth medical and sleep history and physical exam. Centers should be accredited by the American Academy of Sleep Medicine.
Medical and Sleep History
To help determine the presence of sleep apnea, the doctor will ask the following questions:
- Is the patient taking any medications?
- How many periods of sleepiness are there each day and when do they occur? (Patients with apnea often do not describe this symptom as feeling "sleepy." They are more apt to describe this feeling as "lack of energy" or "feeling tired all day.")
- How restful is sleep?
- Do headaches occur regularly in the morning?
- Is the patient taking or withdrawing from stimulants, such as coffee or tobacco?
- How much alcohol is consumed per day?
- Does the patient have any problems with mental or emotional functioning?
- Does the patient suffer from heartburn?
- What is the normal sleeping position (back, side, or stomach)?
- If there is a sleeping partner, does he or she complain about the patient's snoring, thrashing, or gasping for breath? (Many times it is useful to interview the bed partner.)
- Does the patient fall asleep almost as soon as "the head hits the pillow"? (May be a sign of sleep deprivation.)
Keeping a Record of Sleep. To help answer these questions, the patient may need to keep a sleep diary. Every day for 2 weeks, the patient should record all sleep-related information, including responses to questions listed above described on a daily basis. Recording sleep behavior using an extended-play audio or videotape can be very helpful in diagnosing sleep apnea.
To diagnose sleep apnea, the doctor will check for physical indications of sleep apnea, including:
- Abnormalities in the soft palate or upper airways, including enlarged tonsils
- Upper body obesity
- A wide neck measurement (over 17 inches in men or 16 inches in women)
Ruling out Other Disorders
If sleep apnea is not obvious after a physical examination and history, the doctor will need to rule out any other problems. These include sleep disorders, (such as narcolepsy, insomnia, or restless legs disorder), or any medical or psychologic conditions (chronic fatigue syndrome, depression) that may be causing daytime sleepiness.
Sleep testing is recommended for patients who are considered at high risk for complications of obstructive sleep apnea. These include people who are obese, and those who have heart failure, coronary artery disease, or disturbances in heart rhythm.
Polysomnography is the technical term for an overnight sleep study that involves recording brain waves and other sleep-related activity. Polysomnography involves many measurements and is typically performed at a sleep center.
The patient arrives about 2 hours before bedtime without having made any changes in daily habits. Polysomnography electronically monitors the patient as he or she passes, or fails to pass, through the various sleep stages.
Overnight polysomnography has been the gold standard for diagnosing obstructive sleep apnea in both adults and children. It is very labor-intensive and expensive, however, and also misses snoring-induced arousals. After the diagnosis of sleep apnea is made, the patient must come back to the sleep center for another night in order to have CPAP started (CPAP titration).
Split-night polysomnography is an alternative option to overnight polysomnography. In split-night polysomnography, patients who have been diagnosed with obstructive sleep apnea in the first part of the evening, receive titration for CPAP during the second part of the night.
Home Diagnostic Portable Monitors
Diagnostic testing at home with portable monitors may be an option for patients who appear, based on history and physical exam, to have a high likelihood of moderate-to-severe OSA but who do not have other major medical disorders or other sleep disorders such as narcolepsy.
Portable monitors should only be used if the patient receives a comprehensive sleep evaluation by a board-certified sleep specialist. The monitors use nasal and respiratory sensors to record airflow, respiratory effort, and blood oxygen levels. The patient needs to be educated in how to use them by an experienced sleep technician.
Patients are shown how to use these devices and then sent home. Many of these devices are also capable of titrating CPAP levels (see Treatment section).