The D4 HGV Medical, Explained

#What the D4 form is

The D4 is a four-page DVLA medical examination form, completed and signed by a registered medical practitioner. It is the medical evidence the DVLA requires before issuing a Group 2 licence (HGV or PCV). The same form is used for buses, lorries, ambulances, and other commercial categories. The form covers a structured set of questions and physical observations across 12 sections, with the doctor recording findings as they go.

Once the doctor signs it, you submit the form to the DVLA along with your provisional licence application. The DVLA processes the application typically in 4 to 8 weeks, longer if a medical follow-up is needed. The licence is then issued, valid for 5 years (after which you re-medical) or shorter if the DVLA flag a condition that needs annual review.

#Who can do the medical

Any UK-registered medical practitioner can do a D4. In practice, your options are: your own GP (often the slowest route, sometimes not offered at all); a private medical clinic specialising in HGV medicals (faster, slightly more expensive); a chain like LloydsPharmacy or some Boots stores that offer the service; or a few specialist services like medicalsuk.co.uk or medicalsdirect.co.uk that do nothing else. Costs run £60 to £150, with private clinics at the upper end and pharmacy services typically £85 to £100.

The doctor does not need to know you. They are completing a structured form, not making a clinical judgement based on long-term care. Bring your medical history with you (or be ready to recall it) and the appointment runs efficiently.

#What the doctor checks

The D4 covers eight broad areas, each with their own standards.

#Eyesight

You read a Snellen chart at a defined distance with each eye separately, and both eyes together. The standard is 6/9 in the better eye and 6/12 in the worse eye, with corrective lenses if needed (the doctor tests with your normal driving glasses if you wear them). Visual fields are checked, looking for blind spots that would affect peripheral awareness. If you have ever had laser eye surgery or a corneal procedure, declare it on the form. Most refractive procedures do not disqualify but the DVLA wants the history.

#Blood pressure

The doctor takes a sitting BP reading. The DVLA threshold for unrestricted Group 2 is 180/100 mmHg. Above that, the licence may be refused or restricted. Many drivers see "white coat" elevation on the day, especially if anxious about the medical. If your reading is high, the doctor can ask you to relax for 10 minutes and retake it. Persistently elevated BP requires a treatment plan and your GPs sign-off before the licence is granted.

#Cardiovascular history

Heart attacks, angina, irregular heartbeat, pacemakers, valve replacements, and similar conditions all need declaration. Most are not absolute disqualifications, but they trigger DVLA medical adviser review and often result in shorter-validity licences with annual recheck. Be honest. Withholding cardiac history that later surfaces in a roadside check or a hospital admission has stripped drivers of their licence.

#Diabetes

Type 2 controlled by diet alone is straightforward. Type 2 on tablets requires a 3-month BG monitoring history. Insulin-treated diabetes (Type 1, or Type 2 progressed to insulin) has stricter requirements: regular glucose monitoring, episode-free history of severe hypoglycaemia for 12 months, and an annual recheck. Insulin drivers are not refused, but they wear the licence on tighter terms.

#Neurological

Epilepsy, seizures, blackouts, strokes, transient ischaemic attacks (TIAs), Parkinsons, and other neurological conditions need declaration. A single seizure-free year on medication may be enough for some Group 1 (car) licences but Group 2 requires longer seizure-free intervals (typically 5 to 10 years) before the DVLA will grant an HGV licence.

#Sleep apnoea

Obstructive sleep apnoea (OSA) is now a routine D4 question because severe untreated OSA roughly doubles crash risk. The doctor asks about snoring, daytime sleepiness, and witness reports of breathing pauses overnight. If symptoms are present, you may be referred for a sleep study before the licence is granted. Diagnosed and CPAP-treated OSA is licence-compatible (with annual sign-off) but ignored OSA is a problem.

#Mental health

Severe depression, psychosis, bipolar disorder, and a few other conditions need declaration. Most are not licence-disqualifying if managed and stable. Treated and stable conditions are usually fine. Self-medication with alcohol or drugs is a separate, harder issue.

#Substance use

The form asks about alcohol consumption and any history of drug dependence. Honesty is required and routinely tested. Pattern of use that suggests dependence (six or more units a day for men, four or more for women, on a regular basis) prompts further review. Past addiction with a clear recovery period is usually fine.

#Renewal cadence

Once issued, an HGV licence is valid for 5 years before requiring a fresh D4. After age 45, the cycle is also 5 years. After age 65, the cycle shortens to 1 year. After age 70, you re-medical every year and the licence is granted in 1-year increments. There is no upper age limit on HGV driving, but the medical bar gets a little higher each renewal. Maintenance training between medicals runs through periodic Driver CPC.

For the licensing context the medical fits into, see Cat C licence explained, C1 licence explained, and C+E licence. Course providers and pricing benchmarks are at the HGV training school guide.