Explanation of Obstructive Sleep Apnoea

Description of the causes, consequences and treatment of OSA

Obstructive Sleep Apnoea (OSA)

OSA is an increasingly common medical condition. You can think of it as “advanced snoring”.

The reason that most people snore is that the breathing passage behind the tongue is too narrow. This can be for a variety of reasons. It may simply be the way you are built, the anatomy that you have inherited. It can also be because of large tonsils, but most commonly it is the result of increasing weight and accompanying increase in collar size. It is estimated that around 10% of adult men and 4% of adult women suffer from some degree of OSA.

The reason that people don’t snore when they are awake is that there are muscles that pull open this breathing passage, but when you go to sleep the muscles relax and the breathing passage narrows. If you take alcohol or sleeping tablets at night, these are muscle relaxants and the muscles relax more. Similarly as we get older the muscles become “less toned” and don’t work as well. As a result, when you go to sleep the breathing passage narrows to a point where the air going in and out doesn’t flow smoothly any more. It becomes turbulent, and when you get turbulence things vibrate and rattle. This is what snoring is, all the soft floppy bits rattling because the air is being dragged through too small a hole.

If you have OSA the breathing passage narrows even more. When you get into the lovely deep sleep (the sleep that makes you feel refreshed the next day) the muscles relax fully. Now, the breathing passage can collapse completely and even though the chest is trying to get air into the lungs, it can’t. As a result the oxygen levels in the blood start to fall. This sounds dangerous, and it would be if the brain wasn’t doing a surveillance job. The brain recognises the problem and drags you out of the lovely deep sleep, to a lighter level of sleep (but not usually to full consciousness so you do not know anything about these events). Once in the lighter sleep the muscles work again, pull open the breathing passage and you give a loud snore and take a few deep breaths. However, the OSA sufferer then goes straight back into the deep sleep and this cycle can happen literally hundreds of times in the night. As a result you do not get the deep sleep that you need.

The consequence of these repeated arousals from deep sleep is that you feel sleepy during the day, and this makes you more likely to have accidents if you are a driver. It also increases the risk of high blood pressure, diabetes, depression, acid reflux, and getting up to pass urine at night. Male sufferers can also develop erectile dysfunction.

OSA develops over a period of years and individuals often pass off the symptoms as the consequence of getting older. It is only when they are treated that they appreciate just how impaired they had become.

The treatment for OSA depends on its cause and its severity. We all stop breathing occasionally in our sleep (up to 5 times an hour is considered to be normal). If you have severe OSA and are stopping breathing more than 30 times an hour the treatment is to wear a mask connected to a quiet, gentle blowing machine that just adds some pressure to the air that you are breathing. This pushes the breathing passages open and stops them blocking off. If you have good teeth and a milder degree of OSA a special bite guard can help to hold the lower jaw forward when you are asleep and this can cure the problem. If the OSA is caused by weight gain then weight loss is the real cure and this will have huge health benefits. However, if sleepiness is a problem it is important to use one of the other treatments whilst the weight is lost.

If you think that you may have OSA do go and see your doctor and explain your concerns. You should then be referred to a specialist who can investigate this for you and advise on treatment. It is important not to ignore this as the longer it goes on the more impact it will have on your general health.