OSA Medical Abbreviation: Obstructive Sleep Apnea in Plain Words

What the OSA medical abbreviation describes

In obstructive sleep apnea, the muscles that hold the throat open relax during sleep. The soft tissue at the back of the throat sags, and the airway narrows or shuts. The chest and belly keep working to pull in air, but little or none gets through. When oxygen drops, the brain briefly rouses the sleeper, the airway opens with a snort or gasp, and the cycle starts again.

Most people with OSA do not remember waking. What they notice is loud snoring, a dry mouth in the morning, headaches on waking, or feeling unrefreshed after a full night in bed. A bed partner often reports the pauses first. Weight, neck size, jaw shape, large tonsils, alcohol near bedtime and sleeping on the back can all play a part.

OSA versus OSAS and central apnea

The words behind each set of letters matter, because they describe different problems.

Some reports also use OSAHS, adding hypopnea, which means shallow breathing rather than a full stop. In everyday charting, OSA is by far the most common form.

How a sleep study grades severity

The diagnosis usually comes from a sleep study, called polysomnography or PSG, done in a lab or with a simpler home kit. The key number is the AHI, the apnea hypopnea index, which counts breathing pauses and shallow breaths per hour of sleep.

For adults, the usual grading is about 5 to 15 events per hour for mild, 15 to 30 for moderate, and 30 or more for severe. Children are scored on a different, lower scale. Reports also list the lowest oxygen level reached overnight. Sleep centers may word their reports slightly differently, so the interpreting physician's summary is the part that counts.

Where OSA appears in a chart

Because untreated OSA is linked with high blood pressure, heart rhythm problems and daytime sleepiness, clinicians record it in many places. On a problem list it may read "OSA on CPAP." CPAP is continuous positive airway pressure, a bedside machine that blows gentle air through a mask to keep the throat open. Other notes may say "OSA, CPAP noncompliant" when the machine is not being used, or "OSA, s/p UPPP" after throat surgery.

Anesthesia teams pay close attention. A preoperative form may ask whether the patient has known or suspected OSA, and a screening questionnaire may be used to estimate risk. Nurses on a surgical floor may be asked to have the patient bring their own CPAP from home and to watch breathing closely after sedating medicines.

Medical abbreviation OSA for students and scribes

When charting, write OSA in the past medical history if the diagnosis is confirmed, and note the treatment and how well it is used. If a clinician only suspects it, many note "possible OSA, sleep study ordered" rather than listing it as a fact. Coders look for the confirmed diagnosis in the provider's own words.

• Pair OSA with severity when the report gives it: mild, moderate or severe.
• Record the device and settings exactly as ordered.
• Keep OSA separate from snoring alone, which is a symptom, not a diagnosis.

Obesity hypoventilation syndrome has its own page under OHS and can sit alongside OSA in the same person.

Questions to bring to a sleep or primary care visit

A new OSA diagnosis often comes with a machine and a lot of new words. Some useful questions:

• What was my AHI, and what does that grade mean for me?
• Which treatment options fit my results: a pressure device, an oral appliance, position changes or a surgical opinion?
• How will we check that the treatment is working?
• Should my surgeon or dentist know about this before a procedure?