It is a syndrome characterized by repeated collapse of the upper airway during sleep, causing decreased airflow (hypopnea) and cessation of airflow (apnea). This results in sleep fragmentation with frequent arousals which causes symptoms such as excessive daytime sleepiness, personality changes and mental deterioration.
OSAS can occur at any age, including in children. However, it most commonly develops in middle-aged men who are overweight or obese. It is thought that as many as 4 in 100 middle-aged men and 2 in 100 middle-aged women develop OSAS.
Factors that increase the risk of developing OSAS or can make it worse include the following. They all increase the tendency of the narrowing in the throat at night to be worse than normal.
- Overweight and obesity, particularly if you have a thick neck, as the extra fat in the neck can squash your airway.
- Drinking alcohol in the evening. Alcohol relaxes muscles more than usual and makes the brain less responsive to an apnoea episode. This may lead to more severe apnoea episodes in people who may otherwise have mild OSAS.
- Enlarged tonsils.
- Taking sedative drugs such as sleeping tablets or tranquilisers.
- Having a small or receding lower jaw (a jaw that is set back further than normal).
People with OSAS may not be aware that they have this problem, as they do not usually remember the waking times at night. It is often a sleeping partner or a parent of a child with OSAS that is concerned about the loud snoring and the recurring episodes of apnea that they notice.
One or more of the following also commonly occur:
- Daytime sleepiness. This is often different to just being tired. People with severe OSAS may fall asleep during the day, with serious consequences. For example, when driving, especially on long monotonous journeys such as on a motorway. A particular concern is the increased frequency of car crashes involving drivers with OSAS. Drivers with OSAS have a 7-12 increased risk of having a car crash compared to average. You should not drive or operate machinery if you feel sleepy.
- Poor concentration and mental functioning during the day. This can lead to problems at work.
- Not feeling refreshed on waking.
- Morning headaches.
- Being irritable during the day.
You need to undergo a simple test called sleep study or polysomnography to detect your OSAS. A sleep study involves overnight monitoring of your sleep related parameters, oxygen levels with the help of small electrodes.
General measuresThings that can make a big difference include:
- Losing some weight if you are overweight or obese.
- Not drinking alcohol for 4-6 hours before going to bed.
- Not using sedative drugs.
- Stopping smoking if you are a smoker.
- Sleeping on your side or in a semi-propped position.
Continuous positive airway pressure (CPAP)
This is the most effective treatment for moderate or severe OSAS. This treatment involves wearing a mask when you sleep. A quiet electrical pump is connected to the mask to pump room air into your nose at a slight pressure. The slightly increased air pressure keeps the throat open when you are breathing at night and so prevents the blockage of airflow. With CPAP there is an immediate improvement in sleep and other symptoms such as daytime fatigue and snoring.