Mike Lawell posted on October 18, 2008 17:39
Definition
Decompression sickness, also called the bends, is caused by nitrogen bubbles forming in the bloodstream and tissues of the body. The bubbles occur if you move from deep water towards the surface (where the surrounding pressure is lower) in too short a space of time.
Symptoms
Symptoms occur soon after the dive and in the most serious cases can lead to unconsciousness or death.
Headache, vertigo, fatigue are common symptoms. In addition a rash, pain in one or more joints, tingling in the arms or legs, and muscular weakness or paralysis. Less often, shock, unconsciousness, breathing difficulties, or death may be seen.
The symptoms generally appear in a short time after completing the dive. Almost 50% of divers develop symptoms within the first hour after the dive, 90% within six hours and 98% within first 24 hours.
Symptoms after 24 hours rarely are related to DCS. An exception is if the diver has traveled in an aircraft or has been traveling in the mountains. As a result it is not recommended to fly within 24 hours of a deep dive.
What is the Cause
Nitrogen makes up approximately 79% of the air that we breathe. During a dive, large amounts of nitrogen are taken into the body's tissues. This is because the air that the diver is breathing is a higher "dosage" due to the increased pressure of the water at depth.
The quantity of dissolved nitrogen depend on the depth and duration of the dive. The longer and deeper the dive, the more nitrogen that is taken into the body and tissues.
As the diver begins to ascend, the pressure surrounding the body decreases, and nitrogen is released from the body through the lungs as the diver exhales. If the rate of ascent exceeds the rate the nitrogen can be released, it can form bubbles in the blood and tissues.
To minimize the risk of bubbles forming and divers developing decompression sickness, various tables and algorithms have been drawn up that show the relationship between a given depth of water and the time a diver can stay down.
Contributing Factors for DCS
Although there are no guarantees associated, there are many factors that contribute to the propensity to get DCS. The following are among the largest factors for being more susceptible:
- Dehydration
- Obesity
- Cold Water conditions
- Smoking
- Alcohol
- Poor circulation
- Lack of Sleep
- Medications
In addition, diving the limits, ignoring your training can lead to DCS.
Prevention of DCS
The most important step in minimizing DCS is make sure you receive the best scuba open water training with a known agency approved scuba diving school such as Atlanta Scuba. The training received for open water certification should go over in detail the forms of DCS, and the contributing factors for DCS. In addition, you will learn the standards of scuba diving that will increase the safety of scuba diving for the beginner. The following are some the basics that must be followed for the safety of the diver:
- Drink lots of water
- Dive conservatively, within the limits of the dive tables or dive computer.
- Avoid alcohol and drugs before diving.
- Be aware of your physical limits.
- Relax
Talk to your local dive shop and discuss the risks involved with diving. They will answer all of your concerns and have you diving in no time.