What is Sleep Apnea?

diagram man sleep apnea airway closure

Apnea simply means “no breathing”. Sleep apnea is a serious condition where your airway repeatedly closes during sleep, depriving you of oxygen until you gasp awake.

It is a common misconception that all loud snorers have sleep apnea, but if you think you do, ask yourself or your partner if you have any of the following:

  • Loud snoring with periodic silence and choking/gasping
  • Sore throat or headaches in the morning
  • Excessive sleepiness in the daytime
  • Lack of concentration
  • Behavioural changes and mood swings

Snoring, especially loud snoring, puts you at risk of developing sleep apnea later on – as good a reason as any to address your snoring now.

Side note: obstructive vs. central sleep apnea

Sleep apnea comes in two forms; the obstructive condition is linked to snoring as there is an airway blockage. The other type, central sleep apnea, is due to a fault in the brain’s regulation of breathing – this type is not linked to snoring. All subsequent references to sleep apnea refer to the obstructive form.

How does sleep apnea differ from normal snoring?

The key difference between snoring and sleep apnea is whether or not you are breathing.

When you produce a snoring sound, you are breathing; air must be travelling through your airways and into your lungs, albeit a bit bumpily. Noise from snoring is bothersome but the more worrying event is when the sound suddenly stops – now you aren’t breathing.

Here, snoring has made the serious transition to obstructive sleep apnea.

Thankfully your body has a mechanism to kick-start breathing again. When it stops for too long, the amount of oxygen in the blood drops and carbon dioxide rises; your brain recognizes this dangerous situation. A fizz of brain activity briefly wakes your body up, often with a gasp or snort. Muscles in your neck open the airways so air can get back into the lungs.

Sadly, when you go back to sleep, this process of obstruction, low oxygen and awakening repeats itself again and again.

Why is sleep apnea dangerous?

Sleep apnea is harmful because repeated oxygen debt and fitful sleep every night takes its toll on your body [1]. During the low oxygen events, your heart is having to work harder. This increases blood pressure which damages your arteries, thickening their walls and increasing the likelihood of:

  • Heart problems including angina, heart failure and heart attacks
  • Stroke
  • Diabetes
  • Impotence

These physical problems are only made worse by disturbed sleep. A lack of sleep also has detrimental effects on your day-to-day mental functioning. Many people experience:

  • Low energy
  • Daytime sleepiness
  • Worsened reaction times
  • Poor memory

Beyond the sufferer, sleep apnea impacts upon society too. At work, persistent tiredness shrinks productivity and means more days taken off sick [2].

On the road, studies have found that people with sleep apnea are twelve times more likely to be involved in road traffic accidents. Some countries now make it mandatory to inform the driver registration authorities if you are diagnosed with sleep apnea [3].

What can put you at risk of sleep apnea?

Snorers are not necessarily suffering from sleep apnea, but the risks associated with each are closely aligned. The things that make you more likely to develop sleep apnea mirror the risk factors for snoring:

  • Obesity
  • Age – this is particularly problematic as older people generally have more fragile hearts and blood vessels
  • Smoking and alcohol
  • Sleeping on your back – more than half of sleep apnea cases are associated with sleeping position
  • Being male
  • Being a post-menopausal female
  • Nasal congestion and mouth breathing

Identifying potential sleep apnea

There are some important things to watch out for if you suspect you have sleep apnea:

  • Very loud snoring, with periodic silence and gasping
  • Headaches or a sore throat in the morning
  • Being excessively sleepy in the day
  • Lack of concentration
  • Mood swings and behavioral changes

Despite continuously waking during the night, sufferers don’t usually realize it themselves. Many people assume that the fatigue they are experiencing is a symptom of age so fail to seek help. Instead, partners of those with the condition are more likely to spot their sleep apnea.

How does sleep apnea severity vary?

The severity of your condition can be assessed by counting how many times you experience low-oxygen events. This helps to generate an AHI score, the apnea-hypopnea index. This measures the apneic or hypopneic episodes per hour of sleep:

  • Apneic episode – complete airflow blockage for at least ten seconds
  • Hypopneic episode – at least 50% reduction in airflow for at least ten seconds

Your AHI score relates to the severity of sleep apnea:

  • 0-5 events per hour – normal
  • 5-15 events per hour – mild sleep apnea
  • 15-30 events per hour – moderate sleep apnea
  • 30+ events per hour – severe sleep apnea

Your score is very important when deciding on the best way to treat your sleep apnea. Mild to moderate cases can be addressed with normal snoring reduction techniques and consumer remedies. If you have a severe case, continuous positive airway pressure devices (CPAP) are the most effective form of treatment.

Conclusion

It is important to know that relatively benign snoring can make a dangerous transition to obstructive sleep apnea. This is a serious condition where your airway repeatedly closes during sleep, briefly depriving you of oxygen until you gasp awake.

Low oxygen events and continuous poor sleep can have serious repercussions on both your physical and mental wellbeing.

The same things that cause snoring put you at risk of sleep apnea. Some people even consider loud snoring to be the first stage of “sub-clinical” sleep apnea. Importantly, up to 95% of people with sleep apnea snore [4], but not everyone who snores has the condition. Understand your risk and know how to spot the signs so you don’t make the switch.

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References

  1. Dempsey JA et al. Pathophysiology of Sleep Apnea. American Physiological Society 2010; 90(1): 47-112. https://doi.org/10.1152/physrev.00043.2008
  2. Dilkes M and Adams A. Stop snoring the easy way and the real reasons you need to. Hachette UK 2017.
  3. Wiseman R. Night School: The Life-Changing Science of Sleep. MacMillan London 2014. P144
  4. Nimrod M and Hanly PJ. Does snoring intensity correlate with the severity of obstructive sleep apnea? Journal of Clinical Sleep Medicine 2010; 6(5): 475-478. https://www.ncbi.nlm.nih.gov/pubmed/20957849

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