Sleep-disordered breathing

Summary

Sleep-disordered breathing (SDB) is a term that describes a group of conditions that are characterised by an abnormal respiratory pattern during sleep. When a sufferer’s body experiences a lack of oxygen, there can be negative long-term health consequences. These include heart disease, stroke, hypertension, diabetes and depression. Symptoms of sleep-disordered breathing include:

• Loud snoring
• Pauses in breathing
• Disturbed sleep

It’s important to note that although most people with SDB do snore, not every snorer will suffer from SDB. The condition is fairly common in the general population, but can contribute to a range of issues for people who have it. Sufferers may experience poor concentration, a lack of focus at work, and an increased risk of traffic accidents. This carries significant economic consequences due to the impact on daytime productivity and healthcare utilisation.

Many people who have SDB are undiagnosed, or not aware they even have it.

Risk factors

• People who are overweight, or obese
• People with predisposed features (small airway, large tongue, large tonsils)
• Middle-aged men
• Menopausal women
• Large neck circumference

Types of sleep-disordered breathing

Obstructive Sleep Apnoea (OSA)

Snoring is caused by the soft tissue in the back of the throat vibrating when the airway relaxes during sleep. But in some cases, the airway becomes so narrow that the walls of the airway stick together and close up. This usually happens for around 10-30 seconds at a time, but can occur for longer – sometimes up to 50 times an hour or even more.

When the airway finally opens up again, the sufferer might emit a loud, violent snore. This event is known as an apnoea. Throughout the night, the sleeper’s body will constantly come out of deep sleep in order to help them breathe – doctors call this an “arousal”. Though they might not be aware of an arousal, this is what causes them to feel sleepy the next day. Sometimes the airway may not fully close, but becomes so narrow that the sufferer experiences an oxygen drop in their blood. This is called a hypopnoea. Frequent apnoeas and hypopnoeas means a person most likely has OSA. 

Central Sleep Apnoea (CSA)

Central Sleep Apnoea (CSA) is a less common form of sleep apnoea. It’s also characterised by apnoeas, but these apnoeas take place in the absence of any effort to breathe. This is due to the brain failing to transmit signals to the muscles that help with breathing.

Upper Airway Resistance Syndrome (UARS)

Upper Airway Resistance Syndrome usually consists of snoring with abnormal airway resistance in the upper airway. This doesn’t lead to apnoeas or hypopnoeas, but leads to arousals during sleep, secondary to the increased effort of breathing. As with sleep apnoea, repeated and multiple arousals result in abnormal sleep routines and daytime sleepiness.