Decompression sickness (DCS), often known as “the bends,” occurs when dissolved inert gases, primarily nitrogen, form bubbles in the body due to rapid reduction in pressure, such as when a diver ascends too quickly. These bubbles can cause a wide range of complications affecting multiple body systems, some of which can be severe or even life-threatening.
The complications of decompression sickness arise mainly from the physical presence of gas bubbles in tissues and blood vessels, which can cause mechanical damage, block blood flow, and trigger inflammatory responses. These complications can be broadly categorized into musculoskeletal, neurological, pulmonary, cutaneous, and cardiovascular effects.
**Musculoskeletal complications** are among the most common and often the earliest signs of DCS. Gas bubbles can form in joints and surrounding tissues, causing intense joint pain, often described as deep, aching, or throbbing. This pain typically affects large joints such as shoulders, elbows, knees, and hips. The discomfort can be severe enough to limit movement and cause an antalgic gait, where the person avoids putting weight on the affected limb. If untreated, joint damage and chronic pain may develop.
**Neurological complications** are more serious and can involve the central and peripheral nervous systems. Bubbles can obstruct blood flow in the brain or spinal cord, leading to symptoms such as numbness, tingling, weakness, paralysis, dizziness, confusion, visual disturbances, hearing loss, and even loss of consciousness. In severe cases, neurological DCS can cause stroke-like symptoms, seizures, or coma. These complications occur because bubbles cause ischemia (lack of blood supply) and direct tissue injury. Neurological DCS is often classified as Type II decompression sickness and requires urgent treatment.
**Pulmonary complications** can occur when bubbles form in the lung’s blood vessels, causing a condition sometimes called “the chokes.” This leads to chest pain, coughing, difficulty breathing, and in severe cases, respiratory failure. Pulmonary DCS is dangerous because it impairs oxygen exchange and can rapidly worsen without prompt intervention.
**Cutaneous complications** involve the skin and lymphatic system. Skin manifestations may include a mottled, marbled appearance known as cutis marmorata, itching, rash, swelling, and small hemorrhages. These skin changes indicate bubble formation in the skin’s blood vessels and lymphatics. While sometimes mild, skin symptoms can be an early warning sign of more systemic involvement and should not be ignored.
**Cardiovascular complications** arise when gas bubbles enter the arterial circulation, a condition called arterial gas embolism (AGE). This can happen if bubbles pass through a heart defect such as a patent foramen ovale (a small opening between the heart’s atria). AGE can cause sudden blockage of blood flow to vital organs, leading to heart attack, stroke, or organ failure. Symptoms depend on the affected organ but can include chest pain, sudden weakness, paralysis, or loss of consciousness.
Other complications related to decompression sickness include **barotrauma**, which is physical damage caused by pressure changes affecting air-filled spaces such as the ears, sinuses, and lungs. Barotrauma can cause ear pain, hearing loss, sinus pain, and lung collapse (pneumothorax), which may complicate DCS treatment.
Treatment of decompression sickness involves recompression therapy in a hyperbaric chamber to reduce bubble size and promote their elimination, along with oxygen administration. However, treatment itself carries risks such as oxygen toxicity, which can cause seizures or lung damage, and barotrauma from pressure changes during recompression.
If decompression sickness is not promptly recognized and treated, complications can progress to permanent disability or death. Early symptoms like joint pain or skin changes should prompt immediate medical evaluation, especially after diving or exposure to rapid pressure changes.
In summary, the complications of decompression sickness are diverse and can affect joints, nerves, lungs, skin
