Last updated: 31 October 2026
Book your HGV / D4 medical with Dr Steve Walton, Sheffield S12: £80, 30-minute GP examination
What is obstructive sleep apnoea?
In OSA the throat repeatedly narrows or closes during sleep, so breathing stops or becomes shallow, often hundreds of times a night. Each episode briefly wakes the brain, so sleep is broken and unrefreshing. Typical signs are loud snoring, pauses in breathing noticed by a partner, waking with a dry mouth or headache, and feeling sleepy during the day. Being overweight, a large neck size, alcohol and sedatives all make it more likely.
Severity is measured on a sleep study as the apnoea-hypopnoea index (AHI), the number of breathing events per hour:
- mild: AHI below 15
- moderate: AHI 15 to 29
- severe: AHI 30 or more
When must a lorry or bus driver tell DVLA?
GOV.UK says you must tell DVLA if you have:
- confirmed moderate or severe OSA with excessive sleepiness
- narcolepsy or cataplexy
- any other sleep condition (including suspected or confirmed mild OSA) that has caused excessive sleepiness for at least 3 months
Lorry and bus drivers use form SL1V. You must not drive until you're free of excessive sleepiness, or your symptoms are controlled and you're keeping to your treatment.
If you have been diagnosed with OSA but have never been excessively sleepy, current guidance does not ask you to notify DVLA.
I would encourage any driver who has excessive daytime sleepiness to get tested. Ask your GP about a referral for a sleep study.
Getting your licence back: what DVLA needs
For moderate or severe OSA with sleepiness, DVLA's guidance for doctors says Group 2 licensing requires:
- control of the condition
- improved sleepiness
- treatment adherence
- medical confirmation of the above, with a review at least once a year for lorry and bus drivers (every 3 years for car drivers)
In practice, the annual review is how your fitness is confirmed. Your sleep clinic downloads data from your CPAP machine, showing how many hours a night you use it, your compliance and your residual AHI (how many breathing events still happen with treatment), and checks that your sleepiness is controlled.
For mild OSA, other sleep conditions and suspected OSA: you must not drive until symptoms are satisfactorily controlled, and if this can't be achieved within 3 months, you must notify DVLA.
Using CPAP as a lorry driver
- Use it every night, including in the cab on nights out. Many machines run from 12/24V with an inverter or a battery pack.
- Keep your clinic appointments. Your annual review is what keeps your licence.
- Tell your sleep clinic you drive professionally. Some clinics prioritise vocational drivers.
- If sleepiness returns (a mask leak, a broken machine, weight gain), stop driving until it's sorted.
Sleep apnoea on the D4 form
Section 6 of the D4 asks whether you have a history or evidence of OSA or another condition causing excessive sleepiness. If so, the doctor records the severity (mild, moderate, severe or not known), date of diagnosis, whether it is controlled, whether you comply with treatment, and the date of your last review. Bring your sleep clinic letter and, if you have it, your CPAP usage report.
At an HGV medical I also ask about daytime sleepiness, snoring and near-misses. Answer honestly. The question is whether you're safe now, and treated drivers usually are.
Common questions drivers ask me about sleep apnoea
"If I get tested, will I lose my licence?" A diagnosis on its own doesn't take you off the road. What matters is whether you're excessively sleepy, and whether treatment controls it. Most drivers who use CPAP properly feel more alert than before. Driving while sleepy and undiagnosed is the real risk, to you, your job and other road users.
"My partner says I stop breathing at night, but I feel fine." Mention it to your GP anyway. Many people underestimate how sleepy they are, because poor sleep has become normal for them.
"Does losing weight help?" Often, yes. Weight loss, cutting down alcohol in the evening and stopping smoking can reduce the severity of OSA. Your sleep team will advise whether you still need treatment.
"What do I tell my employer?" That's between you and your employer, but many transport operators have their own fatigue policies. Being on effective treatment is the strongest position to be in.
Other causes of sleepiness
Shift work, long hours, sedating medicines (some antihistamines, painkillers and antidepressants) and alcohol all add to the risk. DVLA's "Tiredness can kill" leaflet (INF159) is worth reading. If you're sleepy at the wheel, pull over somewhere safe, have a caffeinated drink and a short nap.
Worried you might have sleep apnoea?
See your own GP, who can refer you for a sleep study. Getting diagnosed and treated is better than waiting for a near-miss. For your D4 medical, I examine drivers at Stonecroft Medical Centre, Sheffield S12. It's a full 30-minute assessment for £80.
Book your HGV / D4 medical with Dr Steve Walton, Sheffield S12: £80, 30-minute GP examination
Frequently asked questions
Can I drive an HGV with sleep apnoea?
Usually yes, once it is diagnosed, treated and controlled. Lorry and bus drivers with moderate or severe OSA causing excessive sleepiness must tell DVLA and stop driving until treatment controls their symptoms.
Do I have to tell DVLA I have sleep apnoea?
You must tell DVLA if you have moderate or severe OSA with excessive sleepiness, or any sleep condition causing excessive sleepiness for 3 months or more. Lorry and bus drivers use form SL1V.
How often is sleep apnoea reviewed for HGV drivers?
DVLA's guidance requires Group 2 drivers to confirm review at least annually, compared with at least every 3 years for car drivers.
Will CPAP let me keep my lorry licence?
If CPAP controls your sleepiness and you use it as prescribed, DVLA can license you. They need medical confirmation of control, improved sleepiness and adherence.
What does the D4 ask about sleep apnoea?
Section 6 asks about OSA or other conditions causing excessive sleepiness, the severity (AHI), date of diagnosis, control, treatment compliance and date of last review.
Sources (GOV.UK / DVLA)
- Excessive sleepiness and driving (GOV.UK)
- Assessing fitness to drive, chapter 8: Excessive sleepiness (GOV.UK)
- Tiredness can kill: INF159 (GOV.UK)
Medical standards checked against DVLA's Assessing fitness to drive (November 2025 edition) and GOV.UK guidance, October 2026. Always check GOV.UK for the latest rules.