Decompression Sickness Treatment for Divers: Recompression and the DAN Hotline

Emergency: If you suspect decompression sickness, call the DAN (Divers Alert Network) 24-hour emergency line immediately: 1-919-684-9111. Do not wait for symptoms to worsen. DAN can advise on emergency transport to the nearest recompression facility.

Decompression sickness is treated with recompression in a hyperbaric chamber. Call DAN first. Don’t wait to see whether symptoms improve on their own. Time matters, especially if neurological symptoms are present.

What Causes DCS

When a diver ascends too quickly, dissolved nitrogen in the tissues and blood comes out of solution as bubbles. The same thing happens when you open a carbonated drink quickly — the pressure change releases dissolved gas.

Nitrogen bubbles can form in joints, the spinal cord, the brain, the inner ear, the lungs, and other tissues. Where the bubbles form determines the symptoms.

Type I vs. Type II DCS

Type I DCS involves musculoskeletal and skin symptoms. Joint pain — traditionally called “the bends” — is the most common presentation. The pain is typically dull, deep, and in or around large joints like the shoulder, knee, or elbow. Skin symptoms include mottling, marbling, or an itching rash. Lymphatic involvement causing localized swelling can also occur.

Type I DCS is serious but less immediately life-threatening than Type II.

Type II DCS involves the nervous system, the inner ear, or the lungs. Symptoms include weakness or paralysis, numbness, tingling, visual disturbances, vertigo, imbalance, bladder dysfunction, and extreme fatigue. Pulmonary DCS (“the chokes”) causes chest pain, breathlessness, and cough. Type II DCS can cause permanent paralysis if treatment is delayed.

Any neurological symptom — confusion, weakness, numbness, visual change — after a dive is Type II until proven otherwise. Treat it as an emergency.

Symptoms may appear immediately after surfacing, within minutes, or up to 24 hours later. Delayed onset doesn’t mean the condition is mild.

First Aid on the Surface

While arranging transport to a recompression facility:

Give 100% oxygen via a tight-fitting non-rebreather mask. Surface oxygen at 100% reduces nitrogen bubble size by eliminating the nitrogen gradient and accelerating off-gassing. Every diver group should carry O2 as part of their dive kit.

Keep the diver lying flat and still. Avoid positions that could worsen symptoms.

Hydrate with water or oral rehydration solution if the diver is conscious and not vomiting.

Do not re-dive to treat DCS. This is a well-documented mistake and worsens outcomes.

Do not take the diver to high altitude in an unpressurized aircraft during transport. High altitude increases the effective pressure differential and makes bubble expansion worse. Low-altitude air transport is acceptable with DAN guidance.

Recompression: The Treatment

At a hyperbaric facility, DCS is treated using US Navy Treatment Tables.

US Navy Treatment Table 5 is used for Type I DCS without neurological involvement. Total time in the chamber is approximately 2 hours at a maximum of 2.8 ATA (equivalent to 60 feet of seawater).

US Navy Treatment Table 6 is the standard for Type II DCS with neurological involvement. Minimum time in chamber is 4 hours 45 minutes. This table includes multiple periods at different pressures with oxygen and air breathing cycles. Extension tables exist if the diver doesn’t improve.

Recompression shrinks the nitrogen bubbles, allows gradual off-gassing under controlled conditions, and restores normal tissue oxygenation.

After Treatment: What to Expect

Many Type I cases resolve completely with prompt treatment. Type II DCS, particularly with spinal cord involvement, may leave residual symptoms. Full recovery is possible but depends heavily on how quickly treatment began.

After treatment, your hyperbaric physician will advise on when it’s safe to fly, when to return to diving (if ever), and what follow-up assessments are needed.

DAN provides post-accident resources and can connect patients with hyperbaric medicine physicians experienced in dive accident management.

DAN: Divers Alert Network

DAN is based at Duke University Medical Center and operates a 24-hour emergency line: 1-919-684-9111. They can help identify the nearest available recompression facility, advise on transport logistics, and connect you with hyperbaric physicians.

For non-emergency medical questions about diving health, DAN also maintains a medical information line.

Every diver should have DAN’s number saved before they enter the water.

FAQ

Q: How is DCS treated? Recompression in a hyperbaric chamber using US Navy Treatment Tables. Call DAN at 1-919-684-9111 immediately.

Q: What is the DAN hotline? 1-919-684-9111. Available 24 hours. They locate facilities and guide transport.

Q: What’s the difference between Type I and Type II DCS? Type I is joint pain and skin symptoms. Type II is neurological — weakness, numbness, paralysis. Type II can cause permanent damage without prompt treatment.

Q: Can you re-dive to treat DCS? No. This is dangerous and worsens outcomes. Recompression in a proper chamber is the only treatment.

Related: Decompression Sickness and HBOT | What Is HBOT?

Medical Disclaimer: This content is for informational purposes only and does not constitute medical advice. Decompression sickness is a medical emergency requiring immediate professional evaluation and treatment. Call DAN at 1-919-684-9111 or emergency services immediately if you suspect DCS. This site does not establish a doctor-patient relationship.