Understanding Decompression Sickness Prevention and Causes

Editor: Suman Pathak on Apr 04,2025

 

Decompression sickness (DCS), or "the bends," is a serious risk to scuba divers. It occurs when nitrogen that the body has taken in on a dive develops bubbles when the pressure drops while ascending. With the absence of decompression sickness prevention, pain, organ injury, or death can be the result. This blog shows the causes of DCS and how divers can remain safe with the use of dive tables, safety stops, and other key practices.

What Causes Decompression Sickness?

When you dive deep, water pressure increases, causing your body to absorb extra nitrogen from the breathing air. The deeper and longer you dive, the more nitrogen accumulates in your tissues. When you ascend too quickly, the nitrogen forms bubbles instead of being expelled slowly. The bubbles can restrict blood flow, damage tissues, and cause symptoms like joint pain, dizziness, or paralysis.

How Nitrogen Absorption Works?

Nitrogen absorption is both depth- and time-dependent. Shallow diving enables nitrogen to exit the body without risk, but deep diving is more dangerous because more nitrogen accumulates. Dive tables and dive computers enable you to monitor nitrogen so that you ascend slowly enough not to get DCS.

The Role of Pressure Changes

Sudden changes in pressure while ascending are the primary reason for DCS. Slow, gradual ascent allows nitrogen to escape unharmed. Omitting a safety stop or ascending quickly makes nitrogen create fatal bubbles.

Symptoms of Decompression Sickness

DCS symptoms can manifest within hours or minutes after a dive. These are the usual signs:

  • Joint or muscle aches (usually in shoulders, elbows, or knees)
  • Fatigue, dizziness, or confusion
  • Skin rashes or itching
  • Difficulty breathing or chest pain
  • Numbness, tingling, or paralysis in worst cases

If you feel any of these symptoms, get medical attention immediately. Delays will cause long-term damage.

Decompression Sickness Prevention Tips

Prevention of DCS involves meticulous dive planning and gradual ascent protocols. Take the following steps to minimize risks:

1. Adhere to Dive Tables or a Dive Computer

Dive tables establish safe dive times at various depths, not taking in too much nitrogen. Newer dive computers monitor depth and time real-time, giving ascent rate alerts. Carry one of these devices with you always for decompression sickness prevention.

2. Conduct a Safety Stop

This is a 3-5 minute pause at 15-20 feet (5-6 meters) prior to surfacing. This takes a little more time for the slow removal of nitrogen from your body. A safety stop on shallow dives also lowers the risk of DCS.

3. Regulate Your Rate of Ascent

Rise no faster than 30 feet (9 meters) per minute. Dive computers will trigger too-quick-ascent alarms for most units. Slowing ascent is one of the most effective methods to avoid nitrogen bubbles.

4. Steer Clear of Deep Diving Hazards

Deeper dives necessitate more stringent safety procedures. Below 100 feet (30 meters), nitrogen uptake takes off. Restrict deep dives and always adhere to decompression procedures.

5. Keep Hydrated and Steer Clear of Alcohol

Dehydration makes the blood thicker, and it is more difficult for the nitrogen to get out. Have plenty of water intake before and after diving. Don't consume alcohol, which will dehydrate and raise the risk of DCS.

6. Surface Interval (Wait Between Dives)

When making more than one dive, wait until enough nitrogen has time to depart your body. Dive tables specify good surface intervals. Haste to dive again increases DCS risk.

7. Stay Fit and Healthy

Poor health, obesity, or heart disease raise the chance of DCS. Exercise and good health enable your body to dispose of nitrogen safely.

How Dive Tables Prevent DCS

Dive tables are planning aids that serve to prevent decompression sickness. Dive tables enable divers to calculate maximum dive time at a certain depth within safe bounds of nitrogen. Dive tables prevent DCS because of the following:

  • No-Decompression Limits: These tables tell you how long you can stay at a given depth without having to make mandatory decompression stops.
  • Surface Intervals: The tables will tell you how long to stay on the surface after a dive before you ascend for expulsion of nitrogen.
  • Repetitive Dives: When making repeated dives within a day, the tables take residual nitrogen in your body into account.

Even though dive computers offer instant information, it is nonetheless helpful to be aware of dive tables in the event your gadget breaks down.

The Importance of Safety Stops

A safety stop is a short pause in ascent, typically at 15-20 feet (5-6 meters). Even if your dive computer does not demand it, having a safety stop in your routine is a good idea. Here's why:

  • Extra Off-Gassing Time: It gives your body a few extra minutes to off-gas nitrogen slowly.
  • Reduces Microbubbles: Tiny nitrogen bubbles may form even on safe dives; a safety stop stops them from getting bigger.
  • Emergency Buffer: If you ascend too rapidly by error, a security stop will decrease the danger of DCS.

Deep dives greater than 60 feet (18 meters) cause a few divers to make an extra 5-minute security stop for extra caution.

Deep Diving Risks and Safety Precautions

Deep diving (below 60 feet/18 meters) increases the risk of DCS since higher nitrogen absorption occurs. Major risks are:

  • Shorter No-Decompression Limits: At 100 feet (30 meters), you can have only 20 minutes before needing to make decompression stops.
  • Risk of Narcosis: Nitrogen narcosis can cloud judgment, leading to dangerous ascents.
  • Increased Air Consumption: Most dives consume air more quickly, stressing and potentially making mistakes.

To remain safe:

  • Always keep an eye on depth and time.
  • Use enriched air (Nitrox) to minimize nitrogen exposure.
  • Don't exceed limits—ascend before reaching no-decompression limits.

How Fitness and Health Influence DCS Risk

Overall, health is important in decompression sickness prevention. Factors that enhance risk are:

  • Dehydration: Blood thickness slows the offloading of nitrogen. Stay hydrated by drinking water before and after diving.
  • Alcohol and Caffeine: Both are dehydrating and should not be consumed prior to diving.
  • Obesity: Fatty tissue holds more nitrogen, and this increases the risk of DCS.
  • Fatigue and Stress: Tired divers tend to ascend too rapidly or ignore safety procedures.

Remaining in good physical shape, well-rested, and properly hydrated greatly reduces your risk of DCS.

Emergency Response for Suspected DCS

If you or a dive partner develop DCS symptoms:

  • Provide 100% oxygen immediately.
  • Keep the person lying down and calm.
  • Call for emergency services and make arrangements for a hyperbaric chamber treatment.
  • Do not come down again until completely cleared by a physician.

Other Safety Measures Decompression Sickness Prevention

In addition to the basic precautions, divers must also use these other supplementary safety measures in order to further reduce DCS risks:

1. Correct Buoyancy Control

Good buoyancy prevents jarring changes in depth that will create bubbles. Practice neutral buoyancy techniques regularly and gently ride your BCD up the ascent. A steady, slow ascent is much safer than jerking along the water column.

2. Cold Water Considerations

Cold water diving poses special challenges to avoiding decompression sickness. Cold-induced vasoconstriction reduces nitrogen elimination, making DCS more likely. Dress in proper thermal protection and expect to reduce dive time in cold water. Some divers include additional safety stops in cold water for extra protection.

3. Post-Dive Activity Level

Refrain from physical activity immediately after diving to prevent bubbles from forming. While mobility can enhance circulation, refrain from exercising for a duration, and avoid flying or traveling to altitude for a period of time as well to allow the nitrogen to off-gas completely.

Final Thoughts

Prevention of decompression illness matters to every diver. Knowing the absorption of nitrogen, dive tables, safety stops, and how to control ascent rates, you can reduce the risk of DCS. Safety should always be a priority, particularly when deep diving and signs should never be neglected. Safe diving equals more fun and less risk!

If you remain consistent with these practices, you will be able to enjoy discovering the world beneath the sea while you are protected from decompression sickness.


This content was created by AI