Sleep apnoea

Obstructive Sleep Apnoea (OSA) is a condition that causes sufferers to briefly stop breathing while they are asleep. This interrupts sleep and causes excessive daytime sleepiness. People with OSA are prone to nodding off during the day, and are about seven times more likely to have crashes [1].

Many people that suffer from the condition do not realise it, due to lack of awareness about symptoms. In the UK, it is estimated that around 4% of middle-aged men and 2% of middle-aged women have OSA [2].

How does OSA affect sleep?

OSA is one of the most common medical causes of excessive daytime sleepiness [3]. People with OSA suffer interruptions in their breathing while they are sleeping. The interruptions can last 10 seconds or longer and occur when the muscles around the throat relax too much during sleep. The brain briefly wakes a person up to re-start their breathing, interrupting sleep. Usually the person does not remember waking up so is unaware they have the condition. Because of the repeated waking, sufferers have poor-quality sleep so will feel sleepy during the day and be prone to nodding off [4].

Some people with OSA may only wake a few times in the night, and suffer minimal daytime sleepiness. The more severe form of the condition, where sufferers may wake hundreds of times in the night and suffer severe daytime sleepiness, is known as Obstructive Sleep Apnoea Syndrome (OSAS). OSAS occurs in approximately one in four people with OSA [5].

Fatigue severely impairs your ability to drive safely. For this reason, drivers suffering from untreated sleep apnoea are considered highly dangerous. Sleep scientist Melanie Marshall says, “Untreated, undiagnosed sleep apnoea individuals are more lethal on our roads than individuals who have been drink-driving” [6].

Learn more: Read our fact page on the wider risks of driver tiredness.

Who is most likely to have OSA?

The highest-risk group for OSA are middle-aged men who are overweight, with a collar size of 17 inches or more [7]. However, not all sufferers fit this profile.

Anything that makes the throat narrower (such as enlarged tonsils or set-back lower jaw) means it is easier for the throat to close off and block the airway. Contributory factors can include smoking and drinking (especially before going to sleep) and taking sleeping pills or other sedative medications [8].

Professional drivers such as truck drivers are known to be at higher risk for sleep apnoea. Studies in the USA [9], Australia [10] and Sweden [11] have indicated that 12% to 17% of professional drivers may have OSA. Research has suggested that up to 41% of UK truck drivers have a sleep disorder of some form, with 16% suffering from severe sleep apnoea requiring immediate treatment [12].

What are the symptoms of OSA?

The main symptoms of OSA are snoring and daytime sleepiness. Even slight sleepiness will affect monotonous tasks such as reading, watching TV and driving on trunk roads. If a sufferer’s sleepiness gets worse, it can lead to them falling asleep while talking or eating [13].

Snoring does not necessarily mean a person has OSA, but frequent, very loud snoring together with daytime sleepiness is likely to indicate OSA.

Other symptoms that may indicate OSA include [14]:

  • choking episodes during sleep
  • morning headaches
  • depression
  • waking feeling unrefreshed
  • difficulty concentrating
  • irritability.

The Epworth Sleepiness Scale is a self-assessment test that can be used to determine whether someone is likely to be suffering from OSA. People who score moderate or high risk on this questionnaire should seek medical advice immediately, and may need to notify the Driver and Vehicle Licensing Agency (see below).

What is the law on OSA?

If a tired driver causes a death, they can be charged with death by dangerous driving if evidence proves they were impaired through fatigue. The maximum penalty is 14 years in prison.

If you suffer from OSAS, or OSA with excessive daytime sleepiness, you must inform the DVLA. Group 1 licence holders (car/motorcycle) diagnosed with OSAS must stop driving until the symptoms have been controlled. Group 2 licence holders (lorries and buses) diagnosed with OSAS must stop driving until the symptoms have been controlled, and must have ongoing treatment [15].

How is OSA treated?

OSA is treatable, so anyone who thinks they may be suffering should seek medical advice as soon as possible so they can start getting uninterrupted sleep again. Anyone who drives and thinks they may be suffering should stop driving while they seek diagnosis and treatment, to ensure they are not putting themselves and others at great risk.

Early diagnosis and treatment is also important because, apart from the immediate danger of causing a crash by nodding off at the wheel, untreated OSA increases the risk of high blood pressure, stroke and heart attacks, and can reduce life expectancy by 20% [16].

Referral to a sleep unit will almost always be necessary for suspected sufferers of sleep apnoea so that they can be diagnosed and offered treatment. Some simple approaches are also worth trying to reduce the causes of mild sleep apnoea:

  • losing weight
  • stopping smoking
  • sleeping on your side
  • keeping the nose clear, for example by using a nasal spray, or raising the head end of the mattress
  • reducing or stopping evening alcohol consumption [17].

A person diagnosed with OSA will usually be treated with a continuous positive airway pressure (CPAP) machine, which keeps the throat open with the use of pressurised air. The person must wear a mask, connected to a small pump beside the bed, over their nose during sleep. CPAP machines greatly improve the person’s sleep: sufferers usually notice an immediate, vast improvement in their quality of sleep [18]. Research has found that, for people with OSA, even a few hours’ sleep with a CPAP machine reduces sleepiness at the wheel more than a full nights’ sleep without CPAP [19].

For mild cases of OSA, a mandibular advancement device (MAD) may be more appropriate than a CPAP machine. This is a device like a gum shield, to be worn over your teeth when you are asleep. It is designed to hold your jaw and tongue forward to increase the space at the back of your throat. If you think a MAD may help you, it is recommended that you ask a dentist who is experienced in treating OSA fit one. Buying a ready-made MAD online or from a specialist store is not recommended, as poorly-fitted MADs can make the symptoms worse [20].

In some rare cases, surgery may be an option. However surgery is not often as successful at treating the symptoms as CPAP, and runs the risk of complications, so is usually only considered if all other treatment options have failed and the condition is seriously affecting a patient’s quality of life [21].

Take action: Support Brake’s Driving for Zero campaign to raise awareness of the risks of impaired driving, including sleep apnoea.

How can employers support drivers with OSA?

Under the Health and Safety at Work Act, UK companies and organisations have a responsibility for their employees while they are driving for work purposes. This means that they may be liable for road crashes caused by or involving employees who are suffering from excessive sleepiness.

Brake recommends that companies with staff who drive for work train their drivers and managers to look out for common symptoms. Suspected sufferers should be taken off driving duty immediately and referred for medical assessment. Annual health checks can also help to identify potential OSA sufferers. Research has indicated that medical examinations for drivers that look for common health issues among sedentary workers, such as obesity, hypertension and diabetes, can help identify OSA in drivers who may not have noticed the symptoms themselves [22].

Claire Michell, from the Sleep Apnoea Trust, advises employers to be sympathetic to drivers who may have OSA. Drivers often won’t want to admit there is a problem because they will be scared they will lose their job. Employers can help with this by educating line managers about the condition, particularly the crucial fact that it is treatable.

Learn more: Employers can access guidance from Brake on OSA and a broad range of other road safety topics to help them prevent at-work crashes at

Sources of further information:

[1] Effect of a very low-energy diet on moderate and severe obstructive sleep apnoea in obese men: a randomised controlled trial, British Medical Journal, 2009

[2] Sleep apnoea, NHS Choices, 2014

[3] Excessive daytime sleepiness: A challenge for the practising neurologist, Brain: a journal of neurology, 2001

[4] Frequently asked questions, Sleep Apnoea Trust Association, undated

[5] Sleep apnoea and driving, Real Sleep, 2014

[6] Quoted in: Real Story: Killer in the Cab, BBC 1, 21 November 2005

[7] Frequently asked questions, Sleep Apnoea Trust Association, undated

[8] Sleep apnoea, NHS Choices, 2014

[9] Consensus Criteria for Screening Commercial Drivers for Obstructive Sleep Apnea: Evidence of Efficacy, Journal of Occupational & Environmental Medicine, 2008

[10] Sleepiness, Sleep-disordered Breathing, and Accident Risk Factors in Commercial Vehicle Drivers, American Journal of Respiratory and Critical Care Medicine, 2004

[11] Sleep debt, sleepiness and accidents among males in the general population and male professional drivers, Accident Analysis & Prevention, 2003

[12] Respironics SASA research, presented in: Real Story: Killer in the Cab, BBC 1, 21 November 2005

[13] Frequently asked questions, Sleep Apnoea Trust Association, undated

[14] Sleep apnoea and driving, Real Sleep, 2014

[15] Ibid.

[16] Ibid.

[17] Sleep apnoea, NHS Choices, 2014

[18] Treatment of sleep apnoea, Sleep Apnoea Trust Association, undated

[19] One night CPAP withdrawal impairs performance at a driving simulator task, Queensland University of Technology, 2014

[20] Obstructive sleep apnoea – treatment, NHS Choices, 2014

[21] Ibid.

[22] Factors associated with obstructive sleep apnea among commercial motor vehicle drivers, Meharry Medical College, 2011

Page last updated: October 2014

Tags: fatigue tiredness sleep apnoea