What is Decompression Sickness or DCS?


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OpenStax Anatomy and Physiology

A condition known as decompression sickness (DCS) occurs when there is a decrease in pressure on the body and gases are no longer dissolved in blood. The condition affects divers who dives at a very deep high pressure waters and surfaces quickly to a low pressure area. This is similar to the bubbles of gases escaping from a bottle of soda that has just been opened. One of the symptoms includes joint pain which is why the condition is often called “the bends.”

DCS mostly occurs when there is a decrease in barometric pressure. In deep waters, the pressure of the water pressing on the body of a diver is so high. When the diver moves back to the surface where the pressure is low, DCS may occur due to the rapid change in pressure. Lake surfaces in higher mountains have barometric pressure lower than sea level surfaces. It is not surprising that diving in these mountain lakes will result in decompression sickness far more likely than diving in water bodies at sea level.

Similar to the bottled soda concept, DCS causes the gases in blood and other body tissues to come out rapidly in the form of bubbles. The constant air pressure is the one keeping the gases in the blood dissolved. When the air pressure on the body changes from high to low rapidly, dissolved gases may escape and less gas is dissolved in the blood.

Joint pain is the most common symptoms of decompression sickness. Headache and vision problems may also occur. DCS is a serious condition that may lead to death and needs immediate treatment. The main treatment for DCS is putting the patient in a hyperbaric chamber which introduces oxygen to the patient’s body at a very high pressure. The treatment increases the concentration of oxygen in the blood. Most of the time, DCS responds well with a single hyperbaric treatment.

Who are at risk for DCS?

  • Person with congenital heart defects
  • 30 years old and older
  • Female
  • Person with sedentary lifestyle
  • Obese
  • Alcoholic/smokers
  • People who lack sleep
  • Injured
  • Cold water divers
  • Person with lung disease

DCS Symptoms:

  • Joint pain
  • Dizziness
  • Headache
  • Difficulty thinking clearly
  • Extreme fatigue
  • Tingling or numbness
  • Weakness in arms or legs
  • A skin rash

DCS Prevention:

  • Slowly dive and rise in the water
  • Do not stay in your deepest depth longer than the recommended time
  • Wait 24 hours before flying after diving
  • Do not consume alcohol before diving
  • Avoid hot baths after diving
  • Get well hydrated and rested before a scuba dive
  • Talk to your doctor before diving if you have recent serious illness or injuries

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Betts, J. G., Young, K. A., Wise, J. A., Johnson, E., Poe, B., Kruse, D. H., … DeSaix, P. (n.d.). Anatomy and Physiology. Houston, Texas: OpenStax. Access for free at: https://openstax.org/details/books/anatomy-and-physiology