A referrer-facing reference on return-to-diving assessment after pneumothorax. Current UK guidance (UK Diving Medical Committee, reviewed October 2023) permits recreational diving after a spontaneous pneumothorax in two circumstances: bilateral pleurectomy, or five years unoperated and recurrence-free — each conditional on a normal chest CT and lung function. Occupational diving (HSE, military) is held to a higher standard. Dr Lawrence Okiror is a Consultant Thoracic and Robotic Surgeon at Guy’s and St Thomas’, with private practice at London Bridge Hospital and The Lister Hospital Chelsea. Appointments within 2–3 days. Self-referrals welcome.
Last reviewed: July 2026 · Dr Lawrence Okiror FRCS(CTh) FRCSEd(CTh) · GMC 6150382
UKDMC 2023: fit after bilateral pleurectomy or five years unoperated and recurrence-free, with normal CT and lung function.
Pleurectomy failure <1%; VATS pleurodesis alone 5–10% and not regarded as adequate for intending divers.
At-work divers need an HSE AMED certificate (DWR 1997); military diving generally treats spontaneous pneumothorax as disqualifying.
The question that decides the answer is whether the underlying lung has been made safe and whether enough time has passed. A CT and lung function answer the first; the interval since the last episode answers the second. It is not a decision that can be made from the discharge summary.
This is an imaging-led assessment, not a paragraph of advice — and for a patient who wants to dive, the operation that satisfies the standard is a specific one. Refer or request an appointment within 2–3 days →
The concern in diving is not the index pneumothorax but recurrence under pressure. A pneumothorax arising or present at depth expands on ascent by Boyle’s law and can develop into a tension pneumothorax. The assessment therefore exists to answer two questions: has the underlying lung been made safe, and has enough time passed. A chest CT and lung function address the first; the interval since the last episode addresses the second.
The applicable standard depends on whether the patient dives recreationally, at work, or in the forces — three regimes that are often quoted interchangeably but are not equivalent. The section below sets them side by side.
The epidemiology is the justification for caution. Primary spontaneous pneumothorax carries a recurrence rate in the region of 50 per cent, concentrated in the first two years and infrequent thereafter — which is why UK diving guidance uses a five-year recurrence-free interval as one acceptable threshold for the unoperated diver. Risk is strongly modified by smoking, with reported increases of roughly seven-fold for light smoking, twenty-fold for moderate, and up to a hundred-fold for heavy smoking. The male-to-female ratio is about 7:1, and first episodes are uncommon after the age of 40.
Secondary spontaneous pneumothorax reflects underlying lung disease — emphysema, cystic fibrosis and others — and in that setting the lung disease itself usually governs fitness, independently of the pneumothorax. Identifying an occult secondary cause is one of the reasons CT is non-negotiable in this assessment.
A common source of confusion is that these standards are cited as if interchangeable. They are not. The applicable one depends on the diving context, and the endpoint differs accordingly.
| Standard | Applies to | Position on spontaneous pneumothorax |
|---|---|---|
| UKDMC reviewed Oct 2023 | UK recreational sport diving | Fit after bilateral pleurectomy or five years unoperated and recurrence-free; both require normal chest CT and lung function. |
| BTS fitness to dive Thorax, 2003 | Respiratory-physician reference | Contraindication unless treated by bilateral surgical pleurectomy with normal lung function and post-operative CT; VATS pleurodesis deemed inappropriate for intending divers. |
| HSE / DWR 1997 | Divers at work, incl. paid instructors | Annual Certificate of Fitness to Dive from an Approved Medical Examiner of Divers; definitive pleurectomy the realistic route to clearance. |
| Military | Armed-forces diver branch | Generally disqualifying, surgery notwithstanding; individual review only. Merchant-service divers assessed under the HSE route. |
The traumatic pneumothorax pathway sits outside this table: a fully resolved traumatic pneumothorax with normal lung function is not generally treated as a barrier under any of these regimes, because there is a clear precipitant and no inherent tendency to recur.
Where surgery is undertaken specifically to enable a return to diving, the choice of operation is decisive — and this is the point most easily lost when a pleurodesis-type procedure is offered simply to prevent another collapse.
Pleurectomy — generally bilateral for this indication — carries a failure rate well under one per cent, and is the procedure the diving standards are built around. VATS talc or abrasion pleurodesis alone carries a recurrence rate of approximately five to ten per cent.
That is entirely acceptable for a patient whose goal is to reduce recurrence in ordinary life — but it does not meet the threshold for diving, where a recurrence at depth risks a tension pneumothorax on ascent. The indication changes the operation.
Any bulla or blebs identified on CT are addressed at the same procedure. The practical implication for referrers is that a patient who raises a return to diving is best discussed with a thoracic surgeon before a pleurodesis-type procedure is chosen, so the operation matches the intended endpoint rather than closing off the diving route by default.
Consider referral to thoracic surgery when a patient with a history of spontaneous pneumothorax wishes to return to, or take up, diving and does not meet the unoperated five-year-clear criterion; when there have been bilateral or recurrent episodes; when a bulla or blebs are seen on imaging; or when an occupational (HSE or military) standard applies and definitive risk reduction is likely to be required.
The investigations the assessment turns on are a chest CT — required because subpleural blebs and bullae are frequently invisible on plain radiography — and lung function, ideally including the flow-volume loop and gas transfer alongside spirometry. A concise account of the index event (aetiology, side, size, management and any recurrence) and the interval since the last episode should accompany the referral.
One patient-vocabulary point worth pre-empting: patients frequently equate freediving with snorkelling. Surface snorkelling and swimming are safe, but breath-hold diving to depth is not equivalent and should be assessed as diving; the internationally used recreational diver medical now screens freediving under the same rules as scuba. The patient-facing companion, Can I scuba dive after a collapsed lung?, sets this out in lay terms.
UK Diving Medical Committee, pneumothorax standard (reviewed October 2023). British Thoracic Society guidelines on respiratory aspects of fitness for diving (Thorax, 2003). British Thoracic Society Guideline for pleural disease (Roberts ME et al., Thorax, 2023). Health and Safety Executive, Diving at Work Regulations 1997 and MA1 guidance for Approved Medical Examiners of Divers.
This reference is intended for clinicians and describes general assessment principles as of July 2026. It is not medical advice for an individual patient; fitness to dive is determined case by case after review of imaging and lung function. Guidance changes over time — confirm the current position with the relevant diving-medicine authority.
When can a patient be cleared to return to diving after a spontaneous pneumothorax?
Under current UK Diving Medical Committee guidance (reviewed October 2023), an individual with a history of spontaneous pneumothorax may be considered fit for recreational diving in one of two circumstances: after bilateral pleurectomy, or unoperated after five years free of recurrence. Both are conditional on a chest CT and lung function tests showing no significant residual lung disease. The rationale is the high recurrence rate of primary spontaneous pneumothorax (approximately 50 per cent), which is concentrated in the first two years and becomes infrequent thereafter. Clearance is an individualised assessment against imaging and physiology, not a decision that can be made from the history alone.
What workup should accompany a fitness-to-dive referral after pneumothorax?
The two investigations the assessment turns on are a chest CT and lung function tests. CT is required because subpleural blebs and bullae that predict barotrauma risk are frequently invisible on plain chest radiography. Lung function should include spirometry and, where available, the flow-volume loop and gas transfer, since reduced expiratory flow at low lung volumes has been associated with barotrauma. A clear account of the index event — spontaneous versus traumatic, side, size, management, and any recurrence — should accompany the referral, together with the interval since the last episode. For a suspected secondary cause, the underlying lung disease governs the decision.
Does the standard differ for commercial divers and diving instructors?
Yes. Anyone diving at work in the UK — including instructors teaching for payment — falls under the Diving at Work Regulations 1997 and requires an annual Certificate of Fitness to Dive issued by an HSE Approved Medical Examiner of Divers, a separate statutory assessment from the recreational route. For this occupational standard, definitive bilateral pleurectomy with normal CT and lung function is the realistic route back after a spontaneous pneumothorax. Military diving is stricter again, with spontaneous pneumothorax generally treated as disqualifying for the diver branch subject to individual review. Referrers should establish early which regime applies, as it changes the threshold and the endpoint.
Is VATS pleurodesis sufficient for a return to diving?
Not on its own, for the purpose of diving. Keyhole (VATS) talc or abrasion pleurodesis carries a recurrence rate of roughly five to ten per cent, whereas pleurectomy carries a failure rate well under one per cent. The British Thoracic Society fitness-to-dive guidance regards the higher-recurrence procedures as inappropriate where the aim is to return to diving, because a recurrence at depth risks a tension pneumothorax on ascent. Where surgery is undertaken specifically to enable diving, bilateral pleurectomy is the operation that meets the standard, with any bulla or blebs addressed at the same time.
How is a traumatic pneumothorax assessed differently for diving?
A traumatic pneumothorax — following blunt, penetrating or iatrogenic injury — is viewed more leniently than a spontaneous one, because there is a clear precipitant and no inherent predisposition to recurrence. Provided there has been complete resolution of the associated lung pathology, confirmed by the treating team and by lung function, such individuals are not generally considered to be at increased barotrauma risk. Complex injuries with potential for air trapping warrant more detailed imaging. The distinction between spontaneous and traumatic aetiology is therefore central to the assessment and should be made explicit in any referral.
Dr Okiror assesses fitness to dive after pneumothorax with review of CT and lung function, and undertakes definitive bilateral pleurectomy where a return to diving is the goal. Private appointments within 2–3 days at London Bridge Hospital and The Lister Hospital Chelsea. Self-referrals welcome.
Refer or request a consultation →The patient-facing companion, in lay terms: scuba, snorkelling, freediving and the route back
Collapsed Lung TreatmentDiagnosis and keyhole surgery for pneumothorax, and when an operation is recommended
Bullectomy & Giant BullaKeyhole surgery for pneumothorax associated with a bulla or recurrent bullous-disease collapse
Pleural Surgery ReferenceClinical reference on spontaneous pneumothorax (BTS 2023), empyema and pleural malignancy
Flying After a Collapsed LungWhen it is safe to fly after a pneumothorax — full re-inflation confirmed on X-ray, then seven days
For GPs & ReferrersReferral pathways, contact details and what to include when referring to Dr Okiror