Chronic non-healing wounds
Most wounds heal within a few weeks. When one stays open despite proper treatment it is usually called chronic, and the most useful question is normally why it has not healed rather than what else can be added. NICE does not recommend hyperbaric oxygen for diabetic foot ulcers outside a clinical trial, or for pressure ulcers, though some international guidance takes a different view.
This page is written for people whose wound is not healing, their families, and clinicians considering whether hyperbaric oxygen has any place alongside standard care.
If you are unwell, or the wound is spreading, hot, or smelling, get medical help the same day.
When a wound isn't healing as expected
Most cuts, grazes and surgical wounds heal within a few weeks. When a wound stays open despite appropriate treatment, it is usually described as chronic, or non-healing.
For the person living with it, and for their family, that can be frustrating, worrying and sometimes genuinely life-changing. A wound that will not heal can affect mobility, independence, sleep and confidence, as well as carrying a risk of infection and, in some cases, more serious complications.
Many chronic wounds do improve once the underlying cause has been identified and treated properly. That is the most important thing on this page.
Which is why the most useful question is usually not "can hyperbaric oxygen help?" but "why hasn't this wound healed?" The answer to the second question is what should guide every decision that follows, including ours.
Why do some wounds stop healing?
Chronic wounds can look similar to each other while having very different causes. Common ones include:
- Diabetes affecting circulation and nerve function
- Poor blood supply from narrowed arteries
- Problems with the veins returning blood from the legs
- Prolonged pressure on the skin
- Surgical wounds that fail to heal after an operation
- Tissue previously damaged by radiotherapy
Underneath most of them, healing is held back by some combination of reduced blood and oxygen supply to the tissue, infection, ongoing pressure, swelling, and underlying conditions such as diabetes.
Because the causes differ, so does what helps. Something that makes a real difference to one type of wound may do nothing at all for another. That is why this page works through them separately rather than treating chronic wounds as a single condition, and why identifying the cause matters more than treating the surface of the wound.
Standard care always comes first
Before anything else is considered, it is essential that ordinary evidence-based wound care has been properly tried and optimised. For a great many people it is what leads to healing.
The first step is working out why the wound is not healing: examining the blood supply, checking for infection, and identifying the underlying cause rather than treating the wound in isolation. For a leg ulcer that normally includes measuring the ankle brachial pressure index, usually with a hand-held Doppler, before any compression is applied.
From there, treatment is matched to the cause:
- Venous leg ulcers. Compression therapy is the main treatment and the most effective one, alongside dressings and skin care, with referral to consider treating the underlying vein problem.
- Diabetes-related foot ulcers. Taking pressure off the ulcer, known as offloading, together with debridement, infection control, managing any problem with blood supply, and blood glucose control. NICE recommends non-removable casting to offload plantar neuropathic ulcers. For most active diabetic foot problems NICE sets out referral to a multidisciplinary foot care service or foot protection service within one working day, for triage within one further working day. A limb threatening or life threatening foot problem, including ulceration with fever or signs of sepsis, ulceration with limb ischaemia, suspected deep infection or gangrene, should go to acute services immediately.
- Arterial and ischaemic ulcers. Assessment by a vascular service, because restoring blood flow is the treatment wherever that is possible.
- Pressure ulcers. Relieving the pressure, repositioning, appropriate support surfaces, wound care and a nutrition assessment.
Across all of them, removing dead tissue, managing infection, keeping the wound bed appropriately moist and reviewing progress regularly are standard. Care is usually led by a practice nurse, district nurse, tissue viability nurse, leg ulcer clinic or multidisciplinary foot team.
Hyperbaric oxygen should never replace any of this. If it is considered at all, it is only ever alongside the treatment your existing team is already providing.
Where does hyperbaric oxygen therapy fit?
Hyperbaric oxygen therapy means breathing oxygen delivered through a mask inside a pressurised chamber. At increased pressure, considerably more oxygen dissolves into the blood plasma than it would at normal atmospheric pressure.
Since many chronic wounds are short of oxygen, researchers have asked whether raising the amount carried in the blood might support the processes involved in healing. That is the reasoning behind using it in wound care, and it is a reasonable question to ask.
Whether it actually improves healing is a separate question, and one the trials have not answered as clearly as anyone would like. The answer differs considerably depending on the type of wound, the individual patient, and which body is reviewing the evidence.
The next three sections set out where that has landed: what NICE recommends, how other countries have read the same evidence, and what the studies themselves show.
What does NICE recommend?
In the UK, NICE recommends that hyperbaric oxygen therapy is not offered for diabetic foot ulcers other than as part of a clinical trial, and is not offered for pressure ulcers in adults, children or young people.
NHS England does not routinely commission hyperbaric oxygen for any chronic wound indication. Its current service specification funds the treatment for decompression illness and gas embolism only.
Those are two different kinds of decision and worth keeping apart. NICE is making a clinical recommendation. NHS England is making a funding one.
This is the current UK framework and Heal & Go₂ works within it. We would rather set it out plainly than leave you to find it somewhere else.
How does the international picture differ?
Medicine evolves, and health systems reviewing the same evidence sometimes reach different conclusions about it.
The International Working Group on the Diabetic Foot suggests considering hyperbaric oxygen as an additional treatment for carefully selected patients with neuro-ischaemic or ischaemic diabetes-related foot ulcers, where standard care alone has not worked and where the resources to deliver it already exist. It describes that as a conditional recommendation based on low-certainty evidence.
The European Committee for Hyperbaric Medicine makes a similar suggestion for diabetic foot lesions, and a more tentative one for ischaemic ulcers which it ties to oxygen measurements taken inside the chamber. It is explicit that hyperbaric oxygen should never be a stand-alone therapy, and that standard wound care should have been in place for at least four weeks first.
In the United States, Medicare funds hyperbaric oxygen for a narrow group of patients with severe diabetic foot ulcers who meet strict criteria: a wound graded Wagner III or higher, no measurable healing after at least thirty consecutive days of standard care, and use only alongside that care. NICE advises against using the Wagner system in the UK, so that particular criterion does not translate directly.
None of this contradicts NICE. Different bodies weigh the same evidence differently, and they are open about the fact that the evidence is not strong. Understanding why the conclusions differ is more useful than picking whichever one you prefer, and it is the reason a proper individual assessment matters more here than in areas where the evidence is settled. The trials in this area are mostly small, many were not blinded, and the two largest were negative. Where trial evidence is thin, some bodies give more weight to clinical experience and expert consensus than others do. That is the difference, rather than one side having evidence the other has not seen.
What does the evidence currently tell us?
The strongest research has been in people with diabetes-related foot ulcers, and even there the results conflict.
A Cochrane review pooling five trials found more ulcers healed at six weeks with hyperbaric oxygen, but that difference had gone by one year, and the reviewers concluded there was no strong evidence of benefit. Of the individual studies, the one that was properly double-blind found more ulcers healed at one year in a selected group of patients, though NHS England's review questioned how its comparison group was treated. The two largest trials since then did not meet their primary endpoints. There is no established benefit in preventing amputation.
For other wound types the picture is thinner. In venous leg ulcers, a single trial of sixteen people found a temporary reduction in wound size and no increase in the number of ulcers that healed. In arterial and ischaemic ulcers there are no randomised trials at all, and international support rests on expert consensus rather than trial data. In pressure ulcers there are no trials, and NICE recommends against it. For surgical wounds that break down there is no randomised evidence.
Independent reviewers have also not been able to define a "low oxygen wound" as a category that can be reliably identified and treated, which is a real limitation on the reasoning rather than a technicality.
So there is no single answer that applies to everyone. What is reasonable depends on the type of wound, its underlying cause, what has already been tried, and your general health. Where the evidence is weak or absent, we say so on this page rather than leaving it out.
How we assess whether treatment is appropriate
We do not think everyone with a chronic wound should have hyperbaric oxygen. We also do not think everyone should automatically be ruled out. Both of those positions are too simple.
Standard care comes first. Before hyperbaric oxygen is considered at all, ordinary wound care should have been optimised and given time to work. If a wound needs revascularisation, compression or better offloading, those are the treatments, and oxygen is not a substitute for any of them.
Where the evidence is weakest, treatment is rarely appropriate. For venous leg ulcers and for surgical wounds that have broken down, there is little or no evidence of benefit, so hyperbaric oxygen would only very rarely be considered and never as a first step. For pressure ulcers, NICE recommends against it in both adults and children, and we follow that.
Not everyone can have it safely. An untreated collapsed lung rules it out entirely. Other things needing careful assessment include some lung conditions, recent ear or sinus problems, previous ear surgery, uncontrolled seizures, certain chemotherapy drugs, pregnancy and severe claustrophobia. Some medicines and implanted devices need checking first. you have diabetes, blood glucose may need to be checked before and after treatment, and additional monitoring may be required depending on your medication and individual clinical circumstances.
Your existing team stays in charge. If you are under the care of a diabetes team, wound clinic, tissue viability nurse or vascular service, stay with them. Nothing here is a reason to change, pause or delay anything they have recommended. If we treat you we work alongside them, and we write to them.
How the assessment works. We would normally expect a referral from the clinician already treating your wound, and we will always want to speak to them. Our Medical Director reviews each case individually within our clinical governance framework, considering the diagnosis, the underlying cause, what has already been tried, the current evidence, and safety. If hyperbaric oxygen isn't appropriate, we will explain why. If it may have a role, we will discuss the evidence, the limitations and the risks openly before anything is agreed.
Hyperbaric oxygen therapy isn't appropriate for every patient or every type of chronic wound. Some carefully selected people may benefit from specialist assessment. Our role is to work alongside your existing clinical team, look honestly at the evidence for your individual circumstances, and give you a straight answer about whether hyperbaric oxygen is likely to play a useful part in your care. If it isn't, we will tell you.
Common questions
How long should a wound take to heal?
Most wounds heal within two to four weeks. A wound is usually called chronic when it has not healed as expected after four to six weeks of appropriate treatment, or has not healed fully within three months. If yours is not improving, ask the team treating you to reassess the underlying cause.
Is hyperbaric oxygen available on the NHS for a wound like mine?
No. NHS England commissions hyperbaric oxygen for decompression illness and gas embolism only. It does not routinely fund it for any chronic wound, and names diabetic lower limb ulceration specifically among the indications it does not fund.
Will it heal my wound?
Every wound is different, so we cannot predict whether hyperbaric oxygen therapy will improve an individual wound without first understanding its cause, severity, blood supply and the treatment already received.
The evidence for HBOT also varies considerably between different types of chronic wound. For some carefully selected diabetes-related foot ulcers, particularly where blood supply is impaired and appropriate standard wound care has not achieved sufficient healing, international guidelines support considering HBOT as an additional therapy. However, the research remains mixed and UK guidance is more cautious.
This is why we assess each patient individually. HBOT does not replace good wound care, and it will not be appropriate for everyone. Our role is to review your circumstances alongside your existing clinical care and give you an honest, evidence-based opinion about whether HBOT may have an appropriate role in your treatment.
Can HBOT replace my current treatment?
No. Hyperbaric oxygen therapy does not replace the treatment you are already receiving for your wound.
If HBOT is considered appropriate, it is used as an additional therapy alongside established wound care and in collaboration with the healthcare professionals already looking after you.
Treating the underlying cause of a wound remains essential. Depending on your circumstances, this may include compression therapy, pressure offloading, infection management, diabetes management or treatment to improve blood supply.
HBOT cannot replace any of these treatments. European guidance is explicit that it should not be a stand-alone therapy.
At Heal & Go₂, our role is to complement your existing care where there is a clinically appropriate reason to consider HBOT. We would normally work alongside your wound care, diabetes or vascular team rather than asking you to change or stop treatment they have recommended.
Do I need a referral?
We would normally expect one, and we will always want to speak to the team already treating your wound. If you contact us directly, that is the first thing we will ask about. HBOT would not normally be considered until appropriate standard wound care has been optimised and given sufficient time to work.
Is it safe?
It is generally well tolerated but not without risk. The commonest problem is ear discomfort from the pressure change. Temporary short-sightedness is common with longer courses. Seizures are rare. NHS England noted adverse events appear more common with hyperbaric oxygen.
- Clinical and advertising approval
- Approved 3 September 2026 · Dr Anil Dasineni (own revision)
- Reviewed by
- Dr Anil Dasineni, MBBS, DNB (Emergency Medicine), MRCEM. Registered with the General Medical Council with a licence to practise.
- Last reviewed
- 1 October 2026
- Next review due
- 3 September 2027
- Clinical tier
- Tier 1
Sources (10)
www.nice.org.uk/guidance/ng19, www.nice.org.uk/guidance/cg179, www.england.nhs.uk/wp-content/uploads/2018/11/Hyperbaric-oxygen-therapy-services-all-ages-Service-specification-January-2025.pdf, www.england.nhs.uk/wp-content/uploads/2019/04/Hyperbaric-oxygen-therapy-for-diabetic-lower-limb-ulceration-all-ages.pdf, www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD004123.pub4/full, iwgdfguidelines.org/wp-content/uploads/2023/07/IWGDF-2023-07-Wound-Healing-Guideline.pdf, www.echm.org/documents/DHM%202017-Mathieu%20D-Tenth%20European%20Consensus%20Conference%20on%20Hyperbaric%20Medicine.pdf, www.cms.gov/medicare-coverage-database/view/ncd.aspx?ncdid=12, www.nice.org.uk/guidance/qs67/chapter/quality-statement-1-referral-to-a-vascular-service, www.nice.org.uk/guidance/dg52
How we govern clinical content
Clinically governed and CQC-aligned. Heal & Go₂ Medical is working towards CQC registration and does not describe itself as CQC registered.