Diver with suspected decompression sickness also called 'the bends'. DCS can cause join pain and immobility.
Why is Decompression Sickness called the Bends?

Many people hear the term ‘the bends’ but don’t know exactly what it is. I had heard of the term well before my first scuba dive but did not know that it was the same as decompression sickness. As a dive instructor, I explain it to my students on a weekly basis. Today, I will explain it in writing. And what better album to listen to than Radiohead’s ‘The Bends’. But, why is decompression sickness called the bends and where did the term originate from? Well, let’s go back in history a little bit.

Read More: What is Decompression Sickness?

Why is Decompression Sickness Called the Bends?

In fact, ‘the bends’, is used to describe a common sign of Decompression Sickness (DCS). It refers to joint immobility and pain caused by gas bubbles forming in the blood and body tissues. These bubbles often accumulate in joints (such as the elbows and knees) and hinder mobility, which causes a bend in the joint and a bent appearance.

Dissolved gases coming out of solution is what causes decompression sickness. This is either due to rapid ascents or not enough decompression time. This gas can cause bubbles to form in your blood and body tissues.

These bubbles can wreak havoc in your system. It is specifically around the joints where arteries and veins restrict and wrap around a lot of corners. This is how these gas bubbles cause a restriction in the movement of the associated joints. Joints then appear and remain ‘bent’ and hard to move for the victim. This is what happens when you get ‘the bends’.

Find out what divers should do for their own safety to avoid decompression sickness.

Untreated Decompression Sickness can have devastating, long-lasting effects depending on its severity. Even under suspicion or with mild cases it is important to get decompression sickness treatment as fast as possible.

When Was the Term ‘The Bends’ First Used

It is difficult to establish exactly when the term was first used. The term describes signs of decompression sickness. This means it had to develop around a time where decompression sickness was common and known.

The term is found in medical journals from around the time DCS was first discovered and recorded.

DCS can occur in freedivers or in people at altitude, but most commonly occurs after prolonged inhalation of compressed gases.

Some of the earliest work conducted under compressed air on a large scale was the Brooklyn bridge in 1871. To dig the foundations, workers were lowered to the river bed in a ‘bell-shaped caisson of iron’, which is essentially a diving bell. These guys are known as sandhogs, digging many of the underground tunnels and foundations of New York City.

At the end of their working days, these poor workers were pulled up and returned to atmospheric pressure without any form of decompression. As a result of this, they often got decompression sickness and their joints were ‘bent’ out of shape. This is what led to the start of on-going research of DCS.

What is the Bends Scuba Diving?

On earth we are all are saturated with 1 bar of air. Air consists of 21% Oxygen and 79% Nitrogen. The only way we can dissolve additional air into our body is by breathing compressed gas or spending prolonged time in higher pressure air environments.

Breathing higher pressures of air will result in our blood and tissues absorbing more air over time. This stops once the dissolved gases and surrounding gases reach equilibrium.

At 20 meters underwater we are already at 2 bar of pressure. However, it does not actually harm us to fully saturate to 2 bar of air. Gases leaving our blood and tissues too rapidly has the potential to harm us.

Whenever we lower surrounding pressure gas diffuses out of our body. This process has limits before it becomes harmful to us. Imagine a can of soft drink opened to carbonate the syrup inside. This works because the little carbon dioxide trapped in the can is at more than 1 bar of pressure and dissolves into the syrup. We rapidly release the pressure by opening the can, essentially giving the drink decompression sickness.

Long term effects of decompression sickness depend on the severity of the case. Bubbles in our blood vessels can damage their sensitive inner lining causing other material to stick to the insides of arteries and veins. Permanent nerve damage and brain damage can also occur in severe cases.

What Happens When You Get the Bends

The most prominent symptoms of decompression sickness (the bends) includes;

  • Local joint pain (mainly in shoulders, elbows, wrists, hips, knees, and ankles)
  • Weakness in the arms and legs
  • Headache
  • Dizziness
  • Trouble thinking clearly
  • Numbness & tingling
  • Extreme fatigue

How to Prevent the Bends

Contrary to popular belief it is actually very easy to avoid decompression sickness. At least within the realm of recreational diving. Safe diving practices teach new divers how to avoid decompression sickness. A large portion of diver training is dedicated to learning about potential risks.

Ascending slowly, staying within No-Decompression limits as well as performing safety stops after every dive are some of the main ways to prevent the bends. Staying in good physical health and well hydrated as well as respecting personal limits are all habitual choices for a conservative diver.

Learn how scuba divers go up and down safely.

New divers are not necessarily at more risk. However, they do tend to be more nervous and conscious of the dangers associated with scuba diving. Because of this, they might be more susceptible to performing a rapid ascent in case of not feeling comfortable. Anxiety can trigger a fight or flight response. New divers will learn how to ascend in scuba diving safely and properly.

Why is decompression sickness called the bends? We have now seen that ‘the bends’ is a slang term that was first used to describe a severe sign of decompression sickness. The immobility and pain caused by gas bubbles in the blood and body tissues.