Avoid Lung Squeeze: Freediving Insights

Freediving is the ultimate underwater experience: you don’t need much equipment and can interact with marine life.You can dive off the shore, not needing to spend too much money on a boat or tank hire and it is super fun and relaxing. Freediving is an exhilarating and rewarding sport, but as with any extreme activity comes the potential for danger. One of the most common risks associated with freediving is a lung squeeze or pulmonary barotrauma. While most experienced freedivers have been able to avoid this type of injury, beginners need to understand how to safely enter the sport and reduce the chances of experiencing a squeeze. 

Freediving is a very safe sport when practiced according to its rules and with the proper guidance gained through freediving courses and earning certifications. However, without the proper guidance or basic knowledge, it could come with some risks. One of the most serious potential dangers is a lung squeeze.

It’s important to understand exactly what causes a lung squeeze and why it’s so dangerous. Whenever the pressure surrounding our bodies increases – as happens when we dive deeper – the air inside our lungs also increases in pressure. This increased pressure causes the air inside our lungs to become more compacted, which in turn squeezes down on our fragile internal tissues. When on land or surrounded by air, your body can adjust its breathing rate and take shallow breaths to compensate, but that is not an option underwater.

What is a Lung Squeeze?

A lung squeeze happens when the diver’s lungs become compressed beyond their flexibility due to pressure changes. The pain associated with a lung squeeze can be excruciating, and in extreme cases, it can even lead to permanent damage or death. In this blog post, we’ll discuss how to avoid a lung squeeze while freediving and some tips to stay safe. 

Tips to stay safe:

• Stretch the thoracic area and keep it flexible. Thoracic flexibility and being able to dive relaxed are key factors when trying to avoid a squeeze. The best way to avoid a squeeze is to keep your lungs and your body flexible to adjust rapidly to pressure and movement. For some tips on lung stretching, read: 5 Exercises to increase your breath-hold for freediving and lung capacity
• Freedive on full lungs only. Advanced freedivers sometimes train on FRC (functional residual capacity), or on a passive exhale. This is very dangerous to do without an instructor and proper guidance. The reason behind this type of training is that when you dive on FRC, you recreate three times the depth where you are. If you are an advanced freediver and want to adapt your body to depth, but you can’t access this depth at your training site, you might find diving to 10 meters on FRC to simulate 30 meters of depth. The slightest movement produces a great amount of pressure in your lungs since they don’t have that extra layer of air to cushion and protect them.
• Slow progressions are the best way to improve. Many freedivers who tried to get deep too fast faced injuries and even death. Freediving is a beautiful sport and lifestyle, but it’s not without its risks. Not even the best are safe from the laws of physics and pressure. The tragic story of Nicholas Mevoli taught us this better than anything else. To read more about his story and the dangers of progressing too fast, read “One Breath” by Adam Skolnick, one of my favourite books. Remember: don’t go too deep too fast
• Let your body have time for adaptation to depth. Just as we need to adapt to high altitude, we need time to adapt to depth. Don’t rush the process. Enjoy the journey!
• Freediving regularly. The best way for your body to adapt to depth and your lungs to get flexible and to progress is to freedive regularly. Take every chance you get to get down to the ocean floor and have a play!
• Move slowly at depth. As we get deeper, fast or big movements can cause us harm. Keep in mind that moving with our bodies under great pressure is not the same as moving on the surface. Be mindful and efficient with your movements at depth and never stretch out your body while deep. 
• Do not dive when you are cold or stressed

The Lungs and the Residual Volume

Our Lungs are amazing organs, capable of expanding and contracting under variances of pressure without us even noticing it. If you are familiar with Boyle’s Law, you’ll know that when the temperature remains unchanged, a pressure increase will result in air being compressed. This happens when we dive: the body of water above and around us increases the pressure exerted on our bodies. As a result, our lungs will compress. Simple: the volume of the air is inversely proportional to the pressure. 

When we freedive, the pressure rises at depth and the volume of the air spaces in our bodies will shrink proportionally to it. As we descend, the lungs compress to their residual volume (RV).

When the lungs are at their RV, a scuba diving equalisation (Valsalva equalisation) technique won’t work and could potentially cause a lung squeeze. Freediving past our RV needs proper guidance and training to avoid injury. It is crucial to equalise using the Frenzel equalisation (where we use the air in our mouth and above the closed epiglottis instead of the diaphragm and the air in our lungs) for deep diving. This maneuver requires less power and significantly decreases the risk of injury to the lungs and diaphragm. 

How the Pressure Affects The Lungs

The lungs, and all cavities in our body filled with air, respond to changes in pressure of their surroundings. When we dive down, they will contract; when we ascend, they will expand as the air inside them returns to its original volume. When the chest compresses to its RV and can’t contract any further, the blood is directed to the lungs. Now, the blood vessels in the lungs swell and decrease even further the volume of the lungs. This is something that our bodies do without us even noticing. It’s one of the beauties of having a mammalian dive reflex (MDR).

Any abrupt movement we make when our lungs are so compressed will have a tremendous effect on the body. Always move with extreme caution at depth. This is why squeezes happen when a freediver is not properly trained or instructed.

Symptoms of a Lung Squeeze

Our lungs don’t have any nerve endings, so the scary part is that we might not even notice that we had a squeeze. Here, trust your instinct: if you feel something is off, cut the dive short and stay safe.

Some symptoms of having a squeeze can be:

• Wheezing
• Shortness of breath
• Feeling you can’t take a full breath
• Feeling tired for no reason
• Coughing some blood

If you think you might have had a squeeze make sure to tell your buddy right away and take the rest of the day off. If possible, breathe oxygen for 10 minutes and see your doctor. 

Always freedive within your limits. Depth and progress will come soon with time and practice. It is the wisest thing to do to increase gradually to deeper levels of diving, giving your body and your lungs time to adjust to bigger pressures one step at a time

How To Progress

• Start by gradual descents. When starting out as a freediver, don’t try diving too deep right away; gradually increase your depth over time until you reach your desired destination. Maintaining a calm mind and listening to your body and intuition during your dives will help prevent sudden movements that could cause a lung squeeze. 
• Be mindful of how far you’re going down. Before each dive, know exactly how deep you plan on going. When you’re starting, always take a buoy and a line with you, or a dive watch to know how deep you are. Don’t exceed your limits without realising it! 
• Keep an eye out for signs of distress during dives, and also keep an eye on your buddy. If at any point during your dive you start feeling dizzy or experience sharp pains in your chest or throat area (both common symptoms of a lung and trachea squeeze), immediately stop descending and ascend back towards the surface. Take a break and make sure you are not injured before returning to dive.
• Dive with experienced freedivers and go out with your teacher on training dives. Evacuate all your doubts and always listen to your body. 
• You are the guru; the guru is in you. I’ll repeat: listen to your body. You must trust yourself and listen to what your body is telling you when diving deep into the ocean depths. If you feel any discomfort or pain related to changing air pressures—even if it’s just minor—it’s best to immediately return before anything worse happens. Additionally, ensure that you take regular breaks during dives so your body has time to adjust without feeling any added stress from depth-related pressure changes. 
• Equalize as frequently as you can. You can’t over-equalise. Equalise as often and as much as you can. As deep dives become more complex due to higher pressures, it becomes even more critical for divers to equalise regularly. This process helps relieve the pressure from your eardrums by moving air from your mouth into the sinuses and into the middle ear. If done improperly or insufficiently, it can cause tremendous pain and pose severe threats like rupturing an eardrum or causing a lung squeeze. 
• Have realistic goals. When learning how to freedive or progress in your freediving journey, it’s important not to push yourself too hard right away. Start shallow and work your way up gradually over time. Your teacher will know when you are ready and comfortable at greater depths. If at any point during your dive you feel pain around your chest area or find yourself struggling while breathing normally, it’s probably time to surface immediately, get dry and reassess your goals. 
• Make sure that after each dive, you practice proper recovery techniques such as coherence breathing or slow breaths for at least five minutes. This will help prevent overexpansion of your lungs.
• Wear Proper Gear: using proper freediving gear can help reduce your chances of getting a lung squeeze while underwater too. Always wear a wetsuit that fits snugly against your body, as its tightness helps prevent drastic changes in air pressure when diving deep into cold waters. Make sure to invest in quality fins explicitly designed for freediving, as they can provide much more efficient propulsion than other types of fins (like those used for swimming or scuba diving). Having fins that propel you with power will prevent you from doing abrupt movements. All these will go far towards not only preventing lung squeezes but also helping improve overall safety during dives.

The Wrap Up

All sports have inherent risks when practicing recklessly, and freediving is no exception. With proper training and guidance, it is a very safe sport that can offer you unlimited adventures and thrills. Learning how to avoid a lung squeeze while freediving is incredibly important if one wants to avoid serious injury while exploring the depths below the water’s surface! 

Practice freediving with care and you will access a whole new dimension and an opportunity to look within yourself and get to know your soul. There is always some risk associated with freediving regardless of how much experience one has; however, following these tips should help reduce that risk significantly–allowing for more enjoyable dives, free from fear and fear of getting a potential lung squeeze.