How can you get decompression sickness

The pain usually occurs in the joints of the arms or legs, back, or muscles. Sometimes the location is hard to pinpoint. The pain may be mild or intermittent at first but may steadily grow stronger and become severe.

Less common symptoms include itching, skin mottling, rash, swelling of the arm, chest, or abdomen, and extreme fatigue. These symptoms do not threaten life but may precede more dangerous problems. The more severe type of decompression sickness most commonly results in neurologic symptoms, which range from mild numbness to paralysis and death.

The spinal cord is especially vulnerable. Symptoms of spinal cord involvement can include numbness, tingling, weakness, or a combination in the arms, legs, or both.

Mild weakness or tingling may progress over hours to irreversible paralysis. Inability to urinate or inability to control urination or defecation may also occur. Pain in the abdomen and back also is common. Symptoms of brain involvement, most of which are similar to those of air embolism, include. Symptoms of inner ear involvement, such as severe vertigo, ringing in the ears, and hearing loss, occur when the nerves of the inner ear are affected.

Symptoms of lung involvement caused by gas bubbles that travel through the veins to the lungs, produce cough, chest pain, and progressively worsening difficulty breathing the chokes. Severe cases, which are rare, may result in shock and death. Dysbaric osteonecrosis sometimes called avascular bone necrosis can be a late effect of decompression sickness, or can occur in the absence of decompression sickness. It involves the destruction of bone tissue, especially in the shoulder and hip.

Dysbaric osteonecrosis Osteonecrosis read more can produce persistent pain and disability due to osteoarthritis resulting from the injury.

These injuries rarely occur among recreational divers but are more common among people who work in a compressed-air environment and divers who work in deep underwater habitats. There is often no specific initiating event the person can identify as the source of symptoms once they do appear.

These workers are exposed to high pressure for prolonged periods and may have an undetected case of the bends. Technical divers, who dive to greater depths than recreational divers, may be at higher risk than recreational divers.

Dysbaric osteonecrosis usually produces no symptoms but if it occurs close to a joint it may gradually progress over months or years to severe, disabling arthritis. By the time severe joint damage has occurred, the only treatment may be joint replacement. Permanent neurologic problems, such as partial paralysis, often result from delayed or inadequate treatment of spinal cord symptoms. However, sometimes the damage is too severe to correct, even with appropriate and timely treatment.

Repeated treatments with oxygen in a high-pressure chamber seem to help some people recover from spinal cord damage. Doctors recognize decompression sickness by the nature of the symptoms and their onset in relation to diving. Tests such as computed tomography CT or magnetic resonance imaging MRI sometimes show brain or spinal cord abnormalities but are not reliable.

MRI is usually diagnostic of dysbaric osteonecrosis. Divers try to prevent decompression sickness by avoiding gas bubble formation. They do this by limiting the depth and duration of dives to a range that does not need decompression stops during ascent called no-stop limits by divers or by ascending with decompression stops as specified in authoritative guidelines, such as the decompression table in Air Decompression, a chapter in the United States Navy Diving Manual.

The table provides a schedule for ascent that usually allows excess nitrogen to escape without causing harm. The computer calculates the decompression schedule for a safe return to the surface and indicates when decompression stops are needed. In addition to following a table or computer guidelines for ascent, many divers make a safety stop of a few minutes at about 15 feet 4. Significant bubble formation can usually be avoided by limiting the depth and duration of dives to a range that does not need decompression stops during ascent called no-stop limits or by ascending with decompression stops as specified in published guidelines eg, the decompression table in the chapter Diagnosis and Treatment of Decompression Sickness in the US Navy Diving Manual.

Many divers wear a portable dive computer that continually tracks depth and time at depth and calculates a decompression schedule. In addition to following published and computer-generated guidelines, many divers make a safety stop for a few minutes at about 4.

However, cases can occur after appropriately identified no-stop dives, and the incidence of decompression sickness has not decreased despite widespread use of dive computers although fewer serious cases occur. Dives 24 hours apart repetitive dives require special techniques to determine proper decompression procedures. Counsel divers to follow established recommendations eg, diving depth and duration, use of decompression stops during ascent that decrease the risk of decompression sickness.

The following English-language resources may be useful. Divers Alert Network : hour emergency hotline, Duke Dive Medicine : Physician-to-physician consultation, Undersea and Hyperbaric Medical Society : Scientific and medical information pertaining to undersea and hyperbaric medicine through its bimonthly, peer-reviewed journal, Undersea and Hyperbaric Medicine , and other resources. From developing new therapies that treat and prevent disease to helping people in need, we are committed to improving health and well-being around the world.

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