If a medical professional thinks you may be suffering from a sleep disorder such as sleep apnea then they will often suggest a sleep study to diagnose exactly what the problem is. Sometimes this can be done in a sleep lab when a device called a polysomnograph (PSG) records information but it can also be done at home and this is what a home sleep study is.
Why stay at home?
There are some clear benefits as to why a home sleep study may be more beneficial and give better results than one in a lab. First is the most obvious; people respond better in their own home and their own bed whereas when staying somewhere unfamiliar, this can alter sleep patterns and skew the test results.
Home sleep studies are also ideal for people who are house bound, elderly or have other chronic illnesses that mean they need the care of a family member or a nurse. It is also ideal for people who work unusual shift patterns that means attending a sleep lab is difficult.
It also works out much cheaper to do the study at home without having any effect on the results of the test.
What happens in the study
The main areas that are studied are the oxygen saturation, heart rate, airflow and effort as well as snoring and sleeping positions. The only things that are done extra in a lab is monitoring brain waves and leg movements.
Usually you can simply collect the device from a scheduled location rather than someone needing to visit the home and is a light and easy to carry device. The common form of the device works by putting a belt around your midsection and attaching a clip on your finger. An airflow sensor goes under your nose and you are ready to turn the machine on.
What kind of conditions are diagnosed?
One of the most common conditions that is diagnosed by this type of study is sleep apnea. It is diagnosed across three levels of severity, which are
- Mild – 5-14 episodes in an hour
- Moderate – 15-30 episodes in an hour
- Severe – more than 30 episodes in an hour
Sleep apnea is a disorder where patients have pauses in breathing or episodes of shallow or infrequent breathing. Every time breathing pauses, this is called an apnea and can last anywhere from ten seconds to several minutes and can occur from five to 30 times an hour. A shallow breathing event is called a hypopnea.
There are two main types of sleep apnea; central and obstructive, though people can have a combination of the two. In CSA, breathing is interrupted due to a lack of respiratory effort while in OSA, this is because of a physical block to airflow despite respiratory effort and snoring is common in these cases. It is thought that around 12 million Americans have OSA and there may be many more cases where people don’t realise they have the condition and it goes unreported.