Editing Decompression sickness (section)

== Prognosis ==
Immediate treatment with 100% oxygen, followed by recompression in a hyperbaric chamber, will in most cases result in no long-term effects. However, permanent long-term injury from DCS is possible. Three-month follow-ups on diving accidents reported to DAN in 1987 showed 14.3% of the 268 divers surveyed had ongoing symptoms of Type II DCS, and 7% from Type I DCS.{{r|UHMS43_Bennett | DAN88}} Long-term follow-ups showed similar results, with 16% having permanent neurological sequelae.{{r|Desola1989}}

Long term effects are dependent on both initial injury, and treatment. While almost all cases will resolve more quickly with treatment, milder cases may resolve adequately over time without recompression, where the damage is minor and the damage is not significantly aggravated by lack of treatment. In some cases the cost, inconvenience, and risk to the patient may make it appropriate not to evacuate to a hyperbaric treatment facility. These cases should be assessed by a specialist in diving medicine, which can generally be done remotely by telephone or internet.{{r|Cronje 2014}}

For joint pain, the likely tissues affected depend on the symptoms, and the urgency of hyperbaric treatment will depend largely on the tissues involved.{{r|Cronje 2014}}

* Sharp, localised pain that is affected by movement suggests tendon or muscle injury, both of which will usually fully resolve with oxygen and anti-inflammatory medication.
* Sharp, localised pain that is not affected by movement suggests local inflammation, which will also usually fully resolve with oxygen and anti-inflammatory medication.
* Deep, non-localised pain affected by movement suggests joint capsule tension, which is likely to fully resolve with oxygen and anti-inflammatory medication, though recompression will help it to resolve faster.
* Deep, non-localised pain not affected by movement suggests bone medulla involvement, with ischaemia due to blood vessel blockage and swelling inside the bone, which is mechanistically associated with osteonecrosis, and therefore it has been strongly recommended that these symptoms are treated with hyperbaric oxygen.