Sleep apnoea is a condition that causes interrupted breathing during sleep. This interruption causes disturbance in an individual’s sleep pattern. Having only limited episodes of deep sleep may leave you feeling very tired the next day. This article will deal with Obstructive sleep apnoea, otherwise known as (OSA). OSA is a condition where your breathing stops for short spells when you are asleep because of an obstruction to the flow of air in your throat at the top of the airway.
What happens in sleep apnoea?
When asleep, the throat muscles relax. In most people, this does not affect their breathing, but in OSA, the muscles in the throat become so relaxed that they collapse, restricting the airway. When your airway is narrowed and the airflow is restricted, this causes snoring. If a complete blockage occurs for around 10 seconds, the blood oxygen levels will drop and this is detected in the brain. During an episode, lack of oxygen causes the person to come out of deep sleep and into a lighter state of sleep, or a brief period of wakefulness, in order to restore normal breathing. You will normally go back off to sleep again quickly and may not even be aware that you have woken up.
There are two types of breathing interruption associated with sleep apnoea:
- apnoea – a complete blockage of the airway for 10 seconds or more, caused by a lack of muscle tone to keep the airway open allowing for normal breathing
- hypopnoea – a partial blockage of the airway that results in an airflow reduction of greater than 50% for 10 seconds or more
Lifestyle changes, such as losing excess weight, can often help mild cases of sleep apnoea. In more severe cases, the use of breathing apparatus while sleeping may be necessary.
Factors that increase the risk of developing OSA include:
- Being Overweight, particularly if you have a large neck, as the extra fat in the neck can squash the airway.
- Drinking alcohol in the evening. Alcohol relaxes muscles more than usual and makes the brain less responsive during an apnoea episode.
- Enlarged tonsils.
- Taking sedative drugs such as sleeping tablets or tranquilisers.
- Sleeping on your back rather than on your side.
- Having a small or receding lower jaw (a jaw that is set back further than normal).
There are several forms of treatment for sleep apnoea. In mild and moderate cases weight loss and the use of mandibular advancement devices may be helpful. In more severe cases, a mandibular advancement device or nasal continuous positive airway pressure (CPAP) may be prescribed.
A CPAP involves wearing a mask when you sleep. An electrical pump is connected to the mask to pump room air into your nose at a slight pressure. This pressure keeps the throat open when you are breathing at night and so prevents the blockage of airflow.
The mandibular advancement device is worn inside the mouth when you sleep. It works by pulling the jawbone forward a little so that your throat may not narrow as much in the night. Although they are available without prescription, it is best to get one properly fitted by a consultant or a dentist if one is recommended.
Surgery is not often used to treat OSA in adults. However, sometimes an operation may be helpful to increase the airflow into your airway, for example if you have any nasal blockages, large tonsils or adenoids.
The content of this article is provided for general information only, and should not be treated as a substitute for the professional medical advice of your doctor or other health care professional