With thanks to Lisa Artis, Deputy CEO of The Sleep Charity 

There is a section on sleep and fatigue later in this guide which addresses the fact that many UK adults – including drivers – routinely get too little sleep and the adverse consequences this has for driving safety. However, many people in the UK have specific sleep disorders, and a high number of these are undiagnosed. This chapter looks at some of the most common sleep disorders and how they can be identified and addressed. 

Why do we need sleep? 

Sleep is not a luxury. It facilitates vital biological functions including: 

• Clearing the brain of toxins and maintaining our nervous system 

• Repairing tissue and injuries 

• Consolidating memory and learning 

Moreover, a long-term lack of sufficient or quality sleep increases risk for many other health conditions, including heart disease, stroke, diabetes and dementia. 

Obstructive sleep apnoea (OSA) 

This condition is often, but not exclusively, diagnosed in people who are significantly overweight or obese. Other conditions such as diabetes, high blood pressure and high cholesterol can also predispose people to OSA.  

OSA narrows or closes the airway during sleep, which in turn forces the person awake in order to breathe. This causes severely disrupted sleep.  

OSA is common, with an estimated 4 million people having moderate or severe OSAS in the UK. NICE calculated in 2018 that 2.5m sufferers were undiagnosed. These figures are likely to be growing as UK obesity levels grow.  

Suspected OSA will mean that a driver must stop driving for a few weeks until their OSA is diagnosed and effectively treated, which can be done with a continuous positive air pressure machine (CPAP). 

Research suggests half of OSA sufferers do not comply with their treatment, which makes vigilance extremely important. 

Narcolepsy 

In narcolepsy the brain's sleep-wake mechanisms are dysfunctional. It is estimated to affect 30,000 people in the UK, but again many cases are undiagnosed.  

Although sometimes narcoleptics fall asleep completely, it is also common for some parts of the brain to sleep while others remain 'awake'. This can lead to automatic behaviours – for instance, a sufferer could continue to type but the resulting words would be gibberish as their language centre is asleep. Or they could continue to drive, holding the steering wheel and changing gear, but have no awareness of what was happening around them. 

Narcolepsy can present with many symptoms:  

• A tendency to fall asleep if bored or passive 

• A tendency to put things in strange, unremembered places – the phone in the fridge etc 

• Difficulties concentrating, following conversations or finding words 

• Cataplexy, which is a sudden loss of muscle control when experiencing high emotion 

• Excessive daytime sleepiness 

• Going straight into dreams on falling asleep, or feeling 'paralysed' while asleep, or 'acting out' dreams 

• Hallucinations (a kind of 'waking' dream) 

Narcolepsy can be diagnosed through sleep studies and measuring the levels of hypocretin in the cerebral spinal fluid. Hypocretin is the neuropeptide which governs alertness, and narcoleptics tend to produce too little. 

Once diagnosed, the condition can be successfully treated with medications.  

Social interaction, movement, caffeine and staying interested is also helpful in maintaining alertness. Boredom, silence and passivity make it harder. Many narcoleptics avoid carbohydrates during periods when wakefulness is required.  

With medical and DVLA approval, people can continue to drive, although they will always have to be aware of and manage their condition.  

In particular, it can be hard for people with narcolepsy to commit to driving long distances, because they cannot know if they will be alert enough for the whole or return journey. Try to plan journeys using routes where it is easy to pull over quickly if necessary. 

Insomnia 

Insomnia affects one in three people in the UK at some point in their adult lives, according to the NHS. 

Insomnia is where you cannot easily fall asleep, or stay asleep, often waking several times during the night, lying there sleepless or waking too early. 

Needless to say, this leaves people very tired and driving is not recommended. 

The cause of insomnia should be determined by a doctor, but anxiety, caffeine, alcohol, nicotine and poor pre-sleep routines can all contribute. 

Shift work sleep disorder 

People working night shifts typically get two to four hours less sleep than those who work daytime shifts. This is because working at night disrupts the body's circadian rhythm and also because daytime can be a disruptive, noisy and distracting time to try to sleep. Shift workers are at greater risk of many common and serious conditions because of this disruption. 

It is very important for shift workers to have good sleep hygiene, to prioritise their sleep quality, and to have a fixed routine – even on their days off. 

Wherever possible, employers should try to avoid rotating shifts. If shift patterns must change, drivers should try to shift their sleep pattern gradually and take naps if necessary. 

Shift workers are far more likely to be involved in a collision when commuting home than other drivers. 

Effect on road safety 

People with sleep conditions are often unaware of them, and many go undiagnosed. However, getting insufficient sleep can cause excessive daytime sleepiness. Sleepiness comprises our ability to think, process our surroundings, learn, respond or regulate our emotions and is extremely dangerous in a driver. 

What employers can do 

• Be aware of drivers who seem tired, 'zone out', yawn or are reliant on caffeine. Have an open, non-judgmental conversation to discover the cause of their tiredness – and if necessary, refer them to their GP. 

• Don't let tired or sleepy drivers drive. 

• Use the Epworth Sleepiness Scale as a quick screening tool for potential sleep issues. 

• Help shift workers to maintain healthy patterns, diet and sleep routines. If possible provide transport home for night-shift workers (with an early shift driver) so they do not have to drive. 

Resources 

Learn more from The Sleep Charity about common sleep disorders here 

This NHS resource is aimed at medical staff but its advice on minimising the health and safety effects of night shifts is relevant to all shift workers.  

Detailed driver information from the Sleep Apnoea Trust about managing sleep apnoea 

The STOP-Bang questionnaire can also be a useful screening tool for OSA.