Obstructive sleep apnea in detail

Obstructive sleep apnea (OSA) is a serious condition where a person’s breathing repeatedly stops while they are asleep. Loud snoring and pauses in breathing are typical features, along with tiredness throughout the day, but there is also a wide range of knock-on effects on other aspects of your cardiovascular and mental health.

This is a full and comprehensive article that explains obstructive sleep apnea, its causes, symptoms, and treatments. 

What is sleep?

Sleep is a vital function. We spend around a third of our lives asleep – that’s over 26 years. Adequate sleep is required to carry out the functions of your daily waking life. It’s a fantastic and complex process we cover in more detail here, but in short, throughout the night we move in a cycle through different stages of sleep, each cycle lasting around 90 minutes. We start in stages of shallow sleep and then move into a deep sleep - which is the important restorative type of sleep that we really benefit from. When we fall deeper asleep, our muscles become more and more relaxed – this fact is key to understanding obstructive sleep apnea.

How do you breathe when you’re asleep?

When we breathe and draw air into our lungs, the air passes first through the upper airway, down the windpipe and into the lungs. The upper airway is made of either rigid structures - which stay in place by themselves or soft structures like at the back of the throat - which need muscles to hold them in position. As we drift into deeper sleep, our muscles become more relaxed – including the muscles that hold the soft parts of our airway open. For most people, this isn’t a problem because their airway is wide enough that there is still plenty of space left for airflow. 

What happens to your breathing when you have obstructive sleep apnea?

If you have OSA , then as the muscles that hold the soft part of the airway start to relax, that part of the airway becomes a lot narrower. The current of air moving back and forth as your breath becomes more turbulent as it flows, and the back of your throat starts to vibrate – which we hear as snoring.

When the muscles are even more relaxed the airway closes, and no air moves at all. We call this an apnea and hear it as a pause in breathing. During this time, oxygen levels in the blood fall.

The body understandably becomes quite anxious at this point. It may tolerate a closed airway for 10 seconds or even longer, but eventually is forced to pull the person back into a shallower state of sleep so that the airway muscles start working again and the airway reopens. People often do this with a loud snort or gasp and might even wake up completely. This event is known as an arousal.

This process of progressive muscle relaxation with airway narrowing, followed by sudden arousal, repeats constantly throughout the night, meaning that someone with OSA has poor quality sleep. Even if they sleep for eight hours they still don't wake up feeling refreshed and are tired all the time.

The severity of OSA is measured by the number of pauses in breathing per hour of sleep. Less than 5 times per hour is considered normal, with 5 to 15 pauses per hour mild, 15 to 30 moderate, and more than 30 pauses per hour being severe OSA.

What are the symptoms and effects of Obstructive Sleep Apnea?

The above process gives rise to a set of symptoms that occur during sleep, such as loud snoring, pauses in breathing, gasping, choking, and startling in sleep. But there are many other symptoms that arise because of OSA, and the resulting poor-quality sleep, which can be grouped according to the body system it affects.

What are the psychological symptoms of Obstructive Sleep Apnea?

We all know what happens after a night of bad sleep - falling asleep during the day, struggling to concentrate, losing our temper. When this happens night after night, the effect can be extremely damaging, both for the person suffering from OSA and those around them. Problems can range from being irritable with friends and family, to poor productivity at work, to having life-threatening car accidents. The British Lung Foundation predicts that if everyone with moderate or severe OSA was treated with CPAP then an extra 40,000 road accidents could be prevented.

What are the cardiovascular symptoms of Obstructive Sleep Apnea?

One of the most important and well-researched systems affected by OSA is the cardiovascular system (heart and blood vessels). OSA increases the risk of coronary heart disease by 30%, the risk of having a stroke by 60% and the risk of heart failure by 140%. The exact mechanism is debated, but the association is clear – OSA leads to greater cardiovascular risk. While some risk factors, such as obesity, are the same for both OSA and cardiovascular disease, even when this is considered, having OSA still acts as an independent risk factor for cardiovascular disease. Additionally, Type 2 diabetes is more common with OSA, which in turn is a significant additional risk for developing cardiovascular disease. There are also higher rates of high blood pressure and an abnormal heart rhythm, called atrial fibrillation in people with OSA.

What are the mental health symptoms of Obstructive Sleep Apnea?

Night after night of poor sleep causes a significant increase in the rates of depression and anxiety. Almost 20% of people with OSA have depression. People frequently find themselves less able to manage their mental health when they are deprived of adequate quality sleep, so even if a diagnosis of depression or anxiety existed before OSA, regular poor-quality sleep can make it worse.

Who gets obstructive sleep apnea?

The short answer is - that anyone can, and lots of people do. The Lancet medical journal predicts more than 8 million people between 30 and 69 years in the UK alone have the condition, and this number is going up. However, there are several factors that make the condition more likely to occur. One of these is increasing age – OSA increases with age up to an 80% prevalence in men over 70. Being overweight is another important risk factor, as it increases the amount of weight pressing in around your neck. Smoking causes inflammation and slight narrowing of the airway which increases the risk further. 

What are the risk factors?

• Being male

• Increasing age 

• Obesity

• Smoking

• Increased alcohol consumption

• Use of sedative medications

• Large neck circumference

While all these factors are useful to know, the important point to make is that anyone can have OSA even if you have none of the risk factors listed above. 

How do you diagnose sleep apnea?

85% of people with obstructive sleep apnea are not aware that they have it. If you have symptoms that are typical of sleep apnea, you should see a specialist sleep doctor. They can listen to your story and how it affects you, ask some key questions and then organise an overnight home sleep apnea test. In our clinic, we use a watch-like device that can be sent to your house by next day delivery. It is worn overnight and can give incredibly detailed information on your sleep. You can see how long you spend in each stage of sleep, whether you snore, if your breathing truly stops and whether your oxygen levels drop as a result. The combination of a consultation with a specialist sleep doctor and the result of a home sleep apnea test can usually confirm a diagnosis of OSA. Once the diagnosis is confirmed, an effective treatment plan can be made.

What treatments are available for obstructive sleep apnea?

While OSA can be an extremely debilitating condition, the good news is that there are effective treatments available. Once you receive a diagnosis of OSA, you can discuss with your sleep specialist what the best treatment is for you as an individual. Broadly speaking there are three treatment options – lifestyle measures, dental devices and continuous positive airway pressure (CPAP).

Lifestyle measures 

If you remember some of the features that make OSA more likely, such as smoking or being overweight, then you can see how focusing on these can improve OSA. Weight loss programmes, smoking cessation and reducing alcohol consumption can all improve your symptoms. If your OSA is mild, then you may find that lifestyle measures alone can stop your OSA entirely. However, it isn’t uncommon to find that such an approach, while it may improve things with OSA, will not eradicate the symptoms. 

Dental devices

For some people, holding the jaw in a slightly different position can alter the shape of the soft airway enough to keep it open during sleep. A mandibular advancement device, also known as an oral appliance, is like a gum shield that fits over the upper and lower teeth and clips together to bring the lower jaw, or mandible, forwards slightly to keep the airway open. They can be made by a specialist dentist, or you can buy a self-moulded device. We recommend S4S dental for specialist devices. They are fairly effective at treating mild or moderate OSA, but generally won’t work in severe OSA.

CPAP

You may have heard of CPAP, or continuous positive airway pressure, as a treatment for OSA. This is a very effective treatment and works by blowing air into either the nose or the mouth at a low pressure that is just enough to hold the soft airway open from the inside. The air is delivered by a small machine that can sit on a bedside table, that connects by tubing to a mask that fits over the nose, or nose and mouth, that is held on by straps that pass around the back of the head. This can seem like a strange idea, but it is extremely effective for mild, moderate, and severe forms of OSA. After a few days of settling in, a long-term sufferer of OSA, who has had poor sleep for years if not decades, will finally be getting a good night’s sleep and their view of CPAP use is usually overwhelmingly positive!

How do I choose the right treatment for Obstructive Sleep Apnea?

Everyone is different, and what may be right for one person will not necessarily be right for another. These options can be discussed with your sleep doctor and a treatment plan that suits you can be discussed and agreed upon. If you have quite mild OSA then lifestyle measures can sometimes be enough to stop the problem, though if you are getting severe enough symptoms then an additional measure is often required. Some people get on well with the dental devices, but they can take a while to get used to and occasionally result in jaw ache. For moderate to severe OSA, most sleep doctors would recommend CPAP, as it is overall the most effective treatment to resolve symptoms. While some people are unsure about the idea of wearing a CPAP mask at night, this is greatly outweighed by the benefits gained from the prompt restoration of deep, effective sleep.

At The Better Sleep Clinic, we have doctors who specialise in the diagnosis and treatment of obstructive sleep apnea. If you are concerned that you or a family member might have OSA then get in touch with one of our specialist sleep doctors today.