Home Sleep Apnea Testing Explained

A simpler overnight test you wear in your own bed, and the limits that come with it.

A home sleep apnea test (HSAT), often called a home sleep test, is a portable device worn for at least one night in your own bed. It records breathing, breathing effort and blood oxygen, but not sleep itself.¹ The AASM accepts it for diagnosing obstructive sleep apnea in adults with signs of moderate-to-severe disease and no complicating conditions.¹ In people at high risk of sleep apnea, standard home tests agree with in-lab results in 84% to 91% of cases, and less often in lower-risk groups.¹

What the Device Records

The AASM defines a technically adequate home test by its sensors. One common design uses a nasal pressure sensor for airflow, belts around the chest and abdomen for breathing effort, and a fingertip oximeter for oxygen. Another uses a finger probe that reads changes in blood vessel tone, paired with oximetry and a wrist motion sensor.¹

What it does not record is brain activity. Without it, the device cannot tell when you are asleep, how deeply, or whether a breathing event woke you briefly.¹

How the Test Works

You receive the device with instructions, attach the sensors at bedtime and sleep as you normally would. The recording is then downloaded and scored, and a qualified clinician reviews it before a result is reported. Most tests cover one night; the guideline’s minimum is a single night of recording.¹

Getting a good recording. Go to bed at your usual time, attach every sensor as shown, and keep the finger probe and nasal sensor in place through the night. If you wake and notice a sensor has slipped, put it back. A recording that loses airflow or oxygen data for much of the night may be reported as technically inadequate.¹

Who It Suits

The guideline recommends a home test, or an in-lab study, for uncomplicated adults whose symptoms suggest moderate-to-severe sleep apnea: loud snoring, witnessed pauses in breathing, daytime sleepiness.¹

It recommends an in-lab study instead for people with significant heart or lung disease, possible breathing-muscle weakness from a neuromuscular condition, suspected hypoventilation, chronic opioid use, a history of stroke, or severe insomnia.¹ In those situations the home test is more likely to miss or misread what is happening. See what happens in a sleep study.

What the Result Means

A home test reports a respiratory event index, or REI: breathing pauses and shallow-breathing episodes per hour of recording. It is read against the same severity bands as the apnea-hypopnea index from a lab study, though the two are not identical, as understanding AHI and REI explains.¹

Accuracy depends on who is tested. In people at high risk of sleep apnea, the guideline’s review found that standard home devices agreed with in-lab results in 84% to 91% of cases. In lower-risk groups the figure fell to 70% to 78%.¹

What a Negative Result Cannot Rule Out

Events that only wake you. The scoring rules count some shallow-breathing episodes because they cause a brief arousal rather than an oxygen dip. A home device cannot see arousals, so those episodes go uncounted.¹

Time spent awake. The REI divides events by recording time, including time lying awake, which pulls the number down.¹

A different night. Sleep apnea varies from night to night. An analysis of more than 67,000 people monitored at home over many months estimated that a single night misclassifies 20% to 50% of people with sleep apnea.²

For these reasons the AASM recommends an in-lab study, not a repeat home test, when a home test is negative, inconclusive or technically inadequate and sleep apnea is still suspected.¹