How to Prevent the Bends (Decompression Sickness)

is scuba diving dangerous

When you are first starting out with scuba diving, there are a few things that you need to worry about. From the basic things like finding the right dive equipment and dive locations, to which scuba certifications you need, to the serious things like whether you will experience the dreaded bends and how to prevent them.

If you’re not aware, ‘the bends’ or decompression sickness (DCS) is an ailment that occurs to people who spend a lot of time at high altitudes or breathes compressed air. It is quite well-known in diving culture, and is sometimes referred to in general culture as well. However, most people aren’t aware of the exact meaning. The symptoms of the bends can affect nearly any body part, such as the lung, heart, skin, brain, and most commonly, the joints.

In this article, we will discuss what the bends actually is as well as provide some general guidelines on how to prevent the bends and some basic treatment methods. Experiencing the bends is a serious matter and should be looked into immediately.

What is ‘The Bends’?

The bends is more formally known as decompression sickness, and it occurs when the body releases gases in the form of bubbles when it comes out of decompression. The bubbles most commonly affect the joints, causing them to bend, however it can also negatively affect the lungs, heart, skin, and brain.

One can limit their exposure to the bends when scuba diving by going through an appropriate decompression process. This involves ascending slowly and making multiple safety stops. Nowadays, all of this is handled by a dive computer which will recommend you a safe ascent rate and alert you when you should perform a safety stop or if you’re ascending too quickly.

With the help of dive computers, divers are less likely to experience the bends as long as they follow the instructions. The dive computers are often quite conservative with their recommendations, so this further limits exposure to DCS. With that said, one can still potentially experience the bends, and it is a serious issue when contracted.

Causes of The Bends (Decompression Sickness)

The bends occurs when the gases in the body are released as bubbles when one goes from a high pressure environment to a lower pressure one. This process is known as depressurization, and when done slowly, is perfectly safe. The issue is when the process is done too quickly and a large amount of bubbles is released in a short time, that is when divers will experience the bends.

To understand why this happens, we have to first explain how pressure affects our body. Normally, on land at sea level, the air around us has 14.7 PSI (pounds per square inch). This is known as one atmosphere of pressure and is what our body is used to. When diving, water pressure increases as one dives deeper. At a depth of 10m (33ft), another 14.7 PSI is exerted on our body, or we can say that there are two atmospheres of pressure at a depth of 10m.

At just 33 feet underwater, our lungs constrict in size by a factor of two since there is now twice as much pressure acting on it. As you dive even deeper, your lungs constrict in size even further. Conversely, when you ascend, your lungs begin to expand to their normal size.

In a similar vein, the air you breathe from your scuba tank has the same amount of pressure that the water is exerting on it. Thus, when diving, you are continuously breathing in compressed air. When you are exposed to this for a prolonged period of time, some of the nitrogen in the air will dissolve into your blood and tissues. They will remain there as long as the pressure remains the same.

Once a diver begins their ascent and the pressure on their body decreases, some of the dissolved gases in your blood and tissue will begin to release. If done slowly, the gases will be released at a slow and safe rate. A fast ascent will cause the dissolved gases in the body to react in the same way as when you shake a can of soft drink and then open the lid. The accumulation of these gases can lead to permanent damage and may even result in death.

How Do I Know If I Have the Bends?

Symptoms of the bends can range from minor to excruciating. Each requires different levels of treatment, depending on the severity and well-being of the individual. Should you or another diver experience any of the following symptoms, put on an oxygen mask and contact a medical professional immediately.

Common Symptoms:

  • Stiffness and pain in the joints. It can be as minor as a dull ache or so painful that it is debilitating.
  • Itchy or swollen skin around the face, neck, or upper body. It can sometimes look marbled.
  • Nausea, dizziness, vertigo, vomiting, loss of balance, etc.
  • Extreme fatigue.
  • Coughing and difficulty breathing.

How to Prevent the Bends

Despite how serious an issue decompression sickness is, thankfully preventing it is straightforward. As we mentioned, issues with the bends arise when divers are ascending too quickly. Therefore, to prevent the bends, divers must limit their ascent rate and occasionally perform decompression stops as recommended by their dive computer. Doing so limits the amount of bubbles released at any point to a manageable, safe level.

Decompression stops are when divers should completely halt their ascent for a period of time. This gives the body time to adjust to that particular depth and for sufficient gases to be released from the body before proceeding upwards.

In the past, deco stops were manually measured and calculated by divers both before and during a diving session. Nowadays, dive computers take out much of the grunt work and limit human errors by doing all of it for you. Dive computers use complex algorithms to determine the body’s uptake and release of inert gases as the pressure changes.

Divers can decrease their deco stop time by using breathing mixtures that contain less inert gas so that they can ascend faster. Divers may also limit how deep they dive so that they do not need to perform any deco stops.

Divers Most Susceptible to the Bends

Some divers are at a higher-risk of experiencing the bends than others. One way to prevent them is to determine if you fall within these categories and consult a medical professional prior to going on a dive. Prevention is much better than a cure, and as you’ll find out in the next section, treating the bends is a lot more difficult than preventing it.

If any of the following applies to you, you are at higher risk of experiencing the bends:

  • You are 30 years of age or older.
  • You have a medical condition affecting your heart or lungs.
  • You smoke or drink alcohol frequently.
  • You tire easily.
  • You are already injured.

The people most at risk of contracting decompression sickness are those who have heart problems, such as having a hole in the heart. While affected by pressure, sometimes blood can re-circulate into the arteries without receiving as much oxygen as it normally does. This can cause weak organs to fail if they are getting less oxygen than usual. Furthermore, having a hole in the heart may let a large bubble circulate into the arteries and cause a stroke.

Similarly, individuals with lung problems may be negatively affected. As you dive deeper, the lung constricts to less than half its usual size due to the water pressure. This can make it hard to breathe, and they may not get enough oxygen. Furthermore, air pockets may develop in the lungs that, when surfacing too quickly, quickly expands and ruptures the lungs.

Treating the Bends

If you or another diver is experiencing the bends, you must call a medical professional. However, in the meantime before help arrives, there are a few things you can do to treat the symptoms of the bends. Understand that you cannot properly treat the bends yourself unless you have access to a hyperbaric chamber.

First, dry the diver and keep warm using blankets. Do not let their body temperature drop. Keep well-hydrated but do not take aspirin for any headaches because it may mask further symptoms, making it harder for medical professionals to gauge the severity of the issue when they arrive. If you have access to oxygen, give the diver a mask as soon as possible.

Second, alert both an emergency service and the Divers Alert Network (DAN) to find where the nearest hyperbaric chamber is and to get specialist advice.

Third, during transportation, the diver needs to lie horizontally. If transported by air, the aircraft should remain below 1,000 feet or be pressurized to sea level pressure. Oxygen should be supplied through a mask until they are transported to the hyperbaric chamber. If the affected individual does not enter a hyperbaric chamber, they may die from the effects of decompression sickness.