Decompression illness, also called "the bends," occurs when nitrogen accumulates in the blood and tissues due to high pressure while diving. Blood oxygen and nitrogen levels are under high pressure during an underwater dive. When a diver ascends too quickly without giving the body a chance to exhale all the nitrogen, air bubbles form in the blood and tissues. The expansion of these bubbles causes damage to tissues and organs, and may cause a blockage in blood vessels.
Type 1 Symptoms
Symptoms usually occur slowly over time and the most common are fatigue, loss of appetite, vague feeling of illness and headache, according to Merck.com. Type 1 or less severe illness affects the musculoskeletal system, with major symptom such as pain in the joints and muscles. Pain begins gradually and becomes more intense over time. Other symptoms may include rash, swollen lymph nodes, extreme fatigue, itching and skin mottling, or patches caused by blood vessel changes. Although these symptoms are not life-threatening, they are a precursor to a serious problem.
Type 2 Symptoms
Type 2 or severe symptoms often involve the brain and spinal cord. Spinal cord symptoms include weakness, tingling and numbness, either combined or separately, in the arms and legs. Tingling and mild weakness may lead to irreversible paralysis, and patients may be unable to urinate or control urination and defecation. Brain symptoms include confusion, double vision, trouble speaking and headaches. Ringing in the ears, severe vertigo and hearing loss may result from damaged ear nerves. If gas bubbles reach the lungs, the symptoms will vary from chest pain and coughing to difficulty breathing. In rare cases, these symptoms can be fatal.
Late Effects
Destruction of bone tissue is common for those who work underwater for prolonged periods. Usually, the shoulder and hip bone is destroyed, leading to severe pain and disability. Joint injuries are also common and lead to severe disabling arthritis that requires joint replacement. Partial paralysis is also common if treatment is delayed.
Air Embolism
An air embolism is a serious condition whereby the oxygen supply is cut off due to air bubbles in the blood. Air bubbles are able to travel to any organ such as the brain, heart, kidneys or skin and block blood supply, causing tissue to die. When the brain is affected, symptoms are very similar to a stroke--confusion, loss of sensation or partial paralysis. This may lead to seizures or sudden loss of consciousness, shock and death.
