What the bends in scuba diving: The Bends: Prevention, Symptoms & Treatment
What are ‘The Bends’? | 4/6/18
‘The Bends’, or decompression sickness to give its proper name, is one of the few dangers to be aware of when scuba-diving. Every diver out there dreads The Bends, and we all take a number of precautions to help keep it at bay every single time we dive – but what exactly is it and how do we avoid it?
Decompression Sickness
When on a normal recreational air-dive, the scuba diver is breathing in approximately 79% nitrogen and 21% oxygen. As we dive deeper, the increased pressure means this nitrogen is absorbed into our body tissue. This isn’t a problem for our bodies when we’re under these pressures, but if that pressure is reduced too quickly the nitrogen can form bubbles which enter the bloodstream and tissues, leading to The Bends. It’s similar to what happens with a fizzy soft drink – when the pressure is released by when it’s opened, bubbles are quickly formed. If you think about how violently gas explodes out of a shaken can or bottle, you get a sense of the potential damage that can be done to the body.
The most common way of getting The Bends (named due to the pain often felt in the joints of your arms or legs) is by going over the decompression limits set on your dive computers or tables, or getting too close to them. However it can also occur even when the diver has followed all the guidelines on the odd occasion.
The bubbles that enter the body tissues lead to a range of symptoms, which usually emerge soon after you surface. Pain is often the first sign, usually in the joints and muscles. Other symptoms include unpleasant itchiness, skin rashes (caused by bubbles in and under the skin) as well as headaches, dizziness, visual impairment, confusion, problems with balance/coordination and nausea. In cases with a great amount of bubbles, lungs can become congested and even brain damage and heart attacks or death can occur.
How to avoid The Bends?
The best way to avoid it is to religiously follow the recommended rate of ascent set by your dive computers! Failing that treatment comes in the form of painkillers for very mild cases, having the divers breathe pure oxygen (which helps speed up the rate that the nitrogen leaves your body), or the use of a hyperbaric or recompression chamber, which expose the sufferer to high pressure causing the nitrogen bubbles to safely leave the tissues.
Finally you should avoid flying within 24 hours of your last dive, as aircraft that are not fully pressurised at altitude can cause nitrogen bubbles to form, even if there was no problems before the flight.
Fisherman Alejandro Ramos Martinez with the funniest ‘Bend’ ever
Other Things Keep The Bends Away
- Never dive right to the limits set by you dive computer, it’s best to always start your ascent at least a few minutes before you reach them.
- The older you are, the less efficient your circulatory system becomes less efficient, which affects the elimination of nitrogen.
- If you’re a bit of a fatty (or big-boned like me) you should know that nitrogen dissolves easily into fat tissue, so chubby funsters may absorb more nitrogen when diving.
- Diving in cold water can cause your extremities to receive less circulation as they cool, which also effects nitrogen elimination.’
- Don’t dive drunk or high! This is something we should never be doing anyway as your judgement will definitely be impaired, but it also makes you dehydrated and raises the heart rate, increasing the risk of those pesky bubbles forming.
- Taking a hot shower or bath after a dive cause your capillaries to dilate, which will draw blood away from other areas which then eliminate nitrogen more slowly.
Safe diving folks!
Treating Decompression Sickness (The Bends)
Decompression sickness (DCS) is one of the most common problems reported to Divers Alert Network® (DAN®). Although scuba diving accidents are rare, it’s important to know how to handle suspected cases of DCS. Your ability to take appropriate action can make a difference in the life of someone you care about.
What is Decompression Sickness?
DCS, also known as the bends, describes a variety of injuries that result from inadequate decompression following exposure to increased pressure. This can occur following uneventful dives within accepted no-decompression limits but is more likely after dives that involve a rapid underwater ascent. DCS can also be prompted by ascending in an airplane too soon after diving.
When there is a rapid decrease in surrounding pressure, nitrogen absorbed by the body at depth comes out of solution, creating bubbles in the bloodstream and/or body tissues.
Symptoms of DCS can occur immediately after surfacing or up to 24 hours later. On average a diver with DCS will experience symptoms between 15 minutes and 12 hours following a dive.
Symptoms of DCS
- Unusual fatigue
- Itchy skin
- Pain in the joints and/or muscles of the arms, legs or torso
- Dizziness, vertigo and ringing in the ears
- Numbness, tingling and paralysis
- Shortness of breath
Signs of DCS
- Blotchy rash
- Muscle weakness or paralysis
- Difficulty urinating
- Confusion, personality changes or bizarre behaviour
- Staggering
- Coughing up bloody, frothy sputum
- Collapse or unconsciousness
How to Treat a Diver with Suspected DCS
If you suspect a diver has DCS, provide emergency oxygen right away.
Next, determine the severity of their condition (emergency, urgent or timely) by following the guidelines below:
Emergency DCS
A diver who is profoundly dizzy, intermittently conscious, weak, walking with an abnormal gait or having trouble breathing is experiencing a serious medical emergency. Administer 100 percent oxygen, and arrange emergency evacuation to the nearest medical facility.
Always contact emergency medical services first, then contact DAN. Although a diver with severe DCS requires recompression, it is essential that he or she be stabilised at the nearest medical facility before transportation to a chamber.
Urgent DCS
A diver experiencing severe pain that is either constant or increasing should be placed on 100 percent oxygen and given fluids. The next step is to contact DAN or the nearest medical facility. Emergency air transportation may not be necessary in all cases. Do not give the diver analgesics (pain relievers) unless advised to do so by medical personnel.
After obtaining professional medical advice, conduct a neurological exam and write down as much information as you can about the diver’s recent diving activity. A neurological exam can be done by anyone; no medical experience or training is required. Simply follow the on-site neuro exam directions found here. Ask the diver about any diving activities within the past 48 hours, including depths, times, ascent rates, surface intervals, breathing gas used and any problems experienced during or after the dives.
Obtain as much info as you can without delaying transportation to a medical treatment facility. If time allows, the following additional information may aid medical professionals with diagnosis and treatment:
- Symptom onset times and progression after the diver surfaced from their last dive
- A list of all first aid measures taken (including times and method of oxygen delivery) and their effect on symptoms
- A description of any joint or other musculoskeletal pain including location, intensity and changes based on movement or weight-bearing maneuvers
- Photos of any rashes with a detailed description of their location
- Information about any traumatic injuries sustained before, during or after the dive
Timely Cases of DCS
Divers who do not have obvious symptoms or whose symptoms develop slowly over multiple days may have a “timely” case of the bends.
Common signs and symptoms may include vague complaints of pain or abnormal sensations.
Follow the steps described previously under “Urgent DCS” to conduct a neurological assessment and collect information about the diver’s recent activity. Next, contact DAN or a medical professional, or go to the nearest medical facility for advice and further evaluation.
Denial: The Worst Symptom of DCS
Denial is arguably the worst “symptom” of DCS. Delayed treatment can lead to permanent injury and prolong (or even prevent) the diver’s full recovery. Emergency oxygen can cause symptoms to temporarily improve only to reappear later — it is no substitute for a medical evaluation. Always contact DAN or a medical professional with training in dive medicine in cases of suspected DCS — even if the symptoms and signs appear to have resolved.
Be Prepared, Get Insured
Dive accidents can happen to anyone, not just newly certified divers. According to a recent DAN Annual Diving Report, nearly 600 divers contacted DAN with concerns about DCS, and divers with 21-60 logged dives were the most likely to report a diving incident.
Learn more about the Top 5 Factors That Increase a Diver’s Risk of Getting the Bends.
Many medical insurance plans cover only the cost of hyperbaric treatments and not the cost of getting you to the chamber (the average cost for an air ambulance is around US$20,000). Ensure you have protection against the unexpected by purchasing DAN Dive Accident Coverage.
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And this means that the more energetically the swimmer moves, the more oxygen he consumes. Accordingly, the easier it will be for a person to move under water, the longer the period of time he will be able to stay there.
To imagine this phenomenon, it is necessary to understand that a certain amount of water, which is captured by the swimmer during the stroke, does not participate in the process of the scuba diver’s movement. But if the side parts of the flippers are more rigid than the inner parts, then it can bend more when stroked, thereby forming a kind of gutter through which more water will flow in the right direction. 
How to choose a snorkel, professional advice
One of the first items that people began to use when exploring the underwater world were breathing snorkels. In the distant past, they were most often made from an ordinary reed stem. Modern models are far superior to them in terms of complexity and variety of design options. To make scuba diving safe and enjoyable, it is important to choose the right snorkel from the large range of models available in our online store.
When making a choice, first of all, consider the application of the accessory you are purchasing.
Scuba Diving
Experience has shown that scuba divers are most comfortable with varieties that have a corrugated segment, such as the Cressi ALFA DRY model. This part allows you to quickly and safely switch from the tube to the device and vice versa while underwater. In addition, the corrugated insert will make it possible to securely hold the tube during diving.
The purchased model must be fixed on the left side of the mask using a special fastener. Fixing under the mask strap when scuba diving is unacceptable: this method dramatically increases the risk of losing the tube.
Pay attention to the fact that the accessory you buy has a silicone mouthpiece, its curve is anatomical, and the shape of the section is an ellipse. A reflector nozzle and bypass valve will be useful.
Underwater swimming (snorkeling)
Scuba is not used in this case, and it is the snorkel that comes to the fore. We recommend opting for a simple model with a rotating silicone mouthpiece, the supply of which is located on the side.
It is important that the mouthpiece design is anatomical, such as that of the IST Favorit Dry model. In this case, the jaws will be less tired, and swimming will be comfortable. Silicone mouthpieces are rightfully considered the most convenient. Rubber varieties are inferior to them in terms of comfort, but last longer.
Pay special attention to snorkel models that allow the replacement of a damaged (e.g. bitten) mouthpiece.
Spearfishing
In this case, the swimmer should be as inconspicuous as possible for the aquatic life, which means that a dark-colored tube is best. A good choice would be a model with a valve that closes the entrance to the tube and eliminates the appearance of gurgling bubbles – for example, IST Saracin.
Snorkel retention requirements for spearfishing are not as stringent as for scuba diving. Many hunters attach an accessory to the mask strap without using additional devices, and in this case this cannot be considered a mistake.