Decompression Sickness from Freediving?


Freediving, with its mesmerizing underwater world and breath-holding challenges, is a captivating water sport. However, it’s essential to address a common question: Can freedivers experience decompression sickness, also known as “the bends,” which is a well-known risk in scuba diving? In this article, we will explore the fascinating world of freediving and its connection to decompression sickness while debunking some myths along the way.

What Are the Bends (Decompression Sickness)?

Decompression sickness (DCS), often referred to as “the bends,” is a potentially serious medical condition that can affect divers and individuals exposed to changes in pressure, such as astronauts and workers in pressurized environments. It occurs when dissolved gases, particularly nitrogen, come out of solution and form bubbles within the body’s tissues and bloodstream due to rapid decompression. Here, we’ll explore the causes, symptoms, risk factors, prevention, and treatment of the bends:


DCS primarily occurs when a person ascends to the surface too quickly after being exposed to high-pressure environments, such as deep-sea diving. The condition is caused by the formation of gas bubbles (mostly nitrogen) in the body as pressure decreases. These bubbles can obstruct blood vessels, damage tissues, and lead to a range of symptoms.


Symptoms of decompression sickness can vary in severity and may include:

  1. Joint pain, often in the shoulders, elbows, knees, or wrists.
  2. Muscle pain and weakness.
  3. Fatigue.
  4. Numbness or tingling sensations.
  5. Dizziness or lightheadedness.
  6. Chest pain or shortness of breath.
  7. Confusion or memory problems.
  8. Nausea and vomiting.
  9. Skin rashes or itching.

In severe cases, DCS can lead to paralysis, unconsciousness, or death if left untreated.

Risk Factors:

Several factors increase the risk of decompression sickness:

  1. Rapid Ascent: Ascending too quickly from a deep dive or pressurized environment is a common risk factor.
  2. Depth and Duration: Diving to greater depths and staying there for extended periods increases the amount of dissolved gases in the body and the risk of DCS.
  3. Repetitive Diving: Engaging in multiple dives within a short time frame without proper surface intervals can increase the risk.
  4. Cold Water: Diving in cold water can increase the risk of DCS due to vasoconstriction, which reduces blood flow to tissues.
  5. Dehydration: Dehydration can worsen the effects of DCS, as it reduces blood flow and increases the concentration of dissolved gases.


Preventing the bends is paramount for divers and individuals working in pressurized environments. Here are key preventive measures:

  1. Safe Ascent: Ascend slowly and follow dive tables or computer algorithms that specify safe ascent rates and surface intervals.
  2. Proper Decompression Stops: Use decompression stops as recommended for the depth and duration of the dive.
  3. Avoid Rapid Ascents: Ascend no faster than the recommended rate, which is typically around 30 feet (9 meters) per minute.
  4. Hydration: Stay well-hydrated before and during dives to reduce the risk of DCS.
  5. Avoid Excessive Alcohol and Caffeine: These substances can dehydrate the body and impair judgment, increasing the risk of DCS.
  6. Dive Training: Proper training in diving techniques and safety procedures is crucial for all divers.


Treatment for the bends usually involves hyperbaric oxygen therapy (HBOT). This treatment involves breathing 100% oxygen while in a hyperbaric chamber at an increased pressure. HBOT helps to:

  1. Reduce Bubble Size: HBOT increases the pressure, which reduces the size of gas bubbles in the body, allowing them to dissolve back into the bloodstream.
  2. Improve Oxygen Delivery: High-pressure oxygen helps to deliver oxygen to damaged tissues and promotes healing.

DCS is a medical emergency, and anyone suspected of having the bends should seek immediate medical attention and be transported to a facility equipped with a hyperbaric chamber. Prompt treatment can significantly improve the chances of a full recovery and minimize long-term effects.

In conclusion, decompression sickness, commonly known as “the bends,” is a potentially serious condition that can occur when individuals are exposed to rapid pressure changes, such as divers ascending too quickly. Understanding the causes, symptoms, risk factors, and prevention measures is crucial for those engaged in activities that involve pressure changes, as early recognition and treatment are key to a successful recovery.

Freediving vs. Scuba Diving

Freediving and scuba diving share the same aquatic playground, but they are fundamentally different. While scuba divers rely on breathing apparatus to explore the depths, freedivers use breath-holding techniques to plunge into the underwater world. The key difference lies in the depth limitation imposed by the freediver’s lung capacity and ability to hold their breath.

Decompression sickness

Understanding the Physiology of Freediving

Understanding the physiology of freediving, also known as breath-hold diving or apnea, is essential for anyone interested in this challenging and exhilarating water sport. Freedivers explore the underwater world without the aid of breathing apparatus, relying solely on holding their breath. To safely and effectively practice freediving, it’s crucial to have a grasp of the physiological adaptations, risks, and techniques involved. Here’s an expanded overview of the physiology of freediving:

1. Breath-Holding Reflexes:

  • Mammalian Dive Reflex (MDR): Humans share the MDR with other marine mammals. When the face is submerged in cold water, the MDR is triggered, resulting in physiological changes to conserve oxygen. These include bradycardia (slowing of the heart rate), peripheral vasoconstriction (narrowing of blood vessels in limbs), and splenic contraction (release of oxygenated red blood cells).
  • Spleen Size: The spleen plays a crucial role in freediving. During breath-holding, it contracts, releasing stored red blood cells, which carry oxygen, into circulation. This helps to prolong the time before hypoxia (oxygen depletion) occurs.

2. Lung Function:

  • Tidal Volume: The amount of air you can inhale and exhale in a normal breath is called tidal volume. Freedivers often train to increase their lung capacity, allowing them to store more oxygen.
  • Residual Volume: This is the volume of air that remains in the lungs after a maximal exhalation. Freedivers aim to reduce their residual volume to maximize the space available for fresh air during inhalation.
  • FRC (Functional Residual Capacity): FRC is the volume of air left in the lungs after a normal exhalation. Freedivers learn to control and extend their FRC to optimize breath-hold times.

3. Blood Oxygen Levels:

  • Oxygen Transport: Hemoglobin in red blood cells carries oxygen to body tissues. When holding their breath, freedivers can reduce their heart rate and peripheral blood flow to extend the time before oxygen depletion occurs.
  • Oxygen Conservation: Freedivers have developed strategies to conserve oxygen, including relaxation techniques, minimizing movement, and breath-hold tables to increase their tolerance to rising carbon dioxide (hypercapnia).

4. Equalization:

  • Ear and Sinus Equalization: Equalization is essential to counteract the increasing pressure on the body as you descend underwater. Freedivers use techniques like the Valsalva maneuver (pinching the nose and blowing gently) to equalize pressure in the ears and sinuses.
  • Lung Squeeze: At deeper depths, the lungs can experience a “squeeze” due to the increasing water pressure. Proper equalization techniques are vital to prevent lung barotrauma.

5. Training and Adaptation:

  • Apgar Score: The Apgar score is a method used to evaluate a freediver’s adaptation to pressure. It considers factors like heart rate, respiratory rate, contractions, and consciousness during a breath-hold.
  • CO2 Tolerance: Increasing CO2 tolerance is crucial for extending breath-hold times. Freedivers practice breath-hold tables and dynamic apnea (underwater swimming on a single breath) to improve their tolerance to rising CO2 levels.
  • Safety and Supervision: Due to the inherent risks of freediving, proper training and safety measures are paramount. Freedivers often train with experienced instructors and follow strict safety protocols.

6. Risks and Safety:

  • Shallow Water Blackout: One of the most significant risks in freediving is shallow water blackout, which can occur during ascent when oxygen levels are critically low. Safety divers and proper surface supervision are essential to prevent accidents.
  • Barotrauma: Pressure-related injuries, such as lung squeeze or ear barotrauma, can occur if equalization is not done correctly.

In conclusion, understanding the physiology of freediving is essential for both safety and performance. Freedivers develop unique adaptations and techniques to explore the underwater world while holding their breath. However, this sport carries inherent risks, and proper training, safety measures, and supervision are crucial to ensure a safe and enjoyable freediving experience.

Can Freedivers Get the Bends?

Freedivers, like scuba divers, can indeed experience decompression sickness (DCS), commonly referred to as “the bends.” While freediving involves breath-hold diving without the use of breathing apparatus, the risk of DCS exists when certain conditions and depths are involved. Here’s an expanded explanation of how freedivers can get the bends and the factors that influence this risk:

1. Depth and Dive Profiles:

  • Shallow Freediving: When freediving in shallow waters, where the pressure changes are minimal, the risk of DCS is relatively low. Most shallow freedives do not involve depths that would necessitate decompression stops.
  • Deep Freediving: The risk of DCS in freediving increases as divers venture deeper. DCS occurs when dissolved gases, primarily nitrogen, come out of solution as pressure decreases during ascent. The deeper the dive, the greater the exposure to increased pressure and the more dissolved gases accumulate in the body.

2. Dive Duration:

  • Extended Dive Times: Longer freedive sessions increase the potential for nitrogen absorption, as the diver remains at depth, allowing the body to take up more nitrogen from the compressed air.

3. Surface Interval:

  • Short Surface Intervals: In freediving, particularly in competitive or training settings, divers may engage in multiple dives with short surface intervals between them. These quick turnarounds don’t allow sufficient time for the body to off-gas (release dissolved nitrogen), increasing the risk of DCS.

4. Hyperventilation:

  • Rapid Breathing: Some freedivers employ hyperventilation techniques to extend breath-hold times. This reduces the body’s carbon dioxide levels, which can suppress the urge to breathe. Hyperventilation can lead to shallow-water blackout, and when combined with deep diving, increases the risk of DCS due to altered gas exchange.

5. Breath-Hold Techniques:

  • Dynamic Apnea: In dynamic apnea (underwater swimming on a single breath), divers may repeatedly dive and ascend, which can increase the accumulation of dissolved gases. This is especially risky when combined with deep dives.

6. Safety and Ascents:

  • Safety Measures: DCS can often be prevented with proper safety measures. Freedivers should have a dedicated safety diver or support team ready to assist during ascents.
  • Ascend Slowly: Just as with scuba diving, ascending slowly can reduce the risk of DCS in freediving. Rapid ascents, especially after deep dives, increase the likelihood of gas bubbles forming in the body.

7. Individual Variability:

  • Diver’s Tolerance: DCS risk can vary among individuals. Some freedivers may have a higher tolerance for pressure changes and nitrogen absorption, while others may be more susceptible to DCS.

It’s important to note that while the risk of DCS exists in freediving, it is relatively low compared to scuba diving, where divers breathe compressed air at depth for extended periods. Many freedivers practice within safe depth limits, engage in proper training, and follow safety protocols to minimize the risk of DCS. Nevertheless, awareness of the potential for DCS is essential, and freedivers should prioritize safety and undergo appropriate training to mitigate these risks.

Preventing Decompression Sickness in Freediving

To minimize the risk of decompression sickness, freedivers should follow safety measures:

  • Gradual Ascents: Ascending slowly allows nitrogen to off-gas from the body gradually.
  • Safety Stops: Taking breaks at specific depths during ascent further aids in off-gassing.

Freediving Safety Practices

Safety is paramount in freediving. Diving with a buddy and having an experienced instructor are crucial safety practices. In the event of an emergency, a buddy can assist, and an instructor can provide guidance to avoid risky behaviors.

Symptoms of Decompression Sickness

Decompression sickness (DCS), commonly known as “the bends,” is a potentially serious and sometimes life-threatening condition that can occur when a person experiences rapid decompression, often due to ascending too quickly from deep water or high-pressure environments. DCS is primarily associated with diving, whether recreational or professional, but it can also affect individuals exposed to changes in pressure, such as astronauts or workers in pressurized environments. Here, we’ll explore the symptoms of decompression sickness in detail:

1. Joint and Muscle Pain:

  • One of the most common and early symptoms of DCS is joint and muscle pain. Divers often describe this pain as a deep, throbbing ache. It typically affects large joints like the shoulders, elbows, knees, and wrists. The pain can range from mild discomfort to severe.

2. Fatigue and Weakness:

  • Individuals with DCS often experience extreme fatigue and muscle weakness. This can make simple movements feel strenuous, and divers may struggle to swim or even climb onto a boat.

3. Dizziness and Lightheadedness:

  • DCS can lead to dizziness and a feeling of lightheadedness. This symptom is often accompanied by impaired coordination, making it challenging to perform tasks that require balance.

4. Numbness and Tingling:

  • Decompression sickness can cause tingling sensations, numbness, or a “pins and needles” feeling in various parts of the body, such as the hands, feet, or face.

5. Chest Pain and Shortness of Breath:

  • DCS may lead to chest pain, which can range from mild discomfort to severe pressure or stabbing pain. Some individuals also experience shortness of breath and difficulty breathing.

6. Nausea and Vomiting:

  • Nausea and vomiting are common symptoms of DCS. These gastrointestinal symptoms can be distressing and may lead to dehydration.

7. Skin Rashes and Itching:

  • Skin rashes, hives, or itching can occur as a result of DCS. These skin-related symptoms can vary in severity and may affect different areas of the body.

8. Vision and Hearing Changes:

  • Some individuals with DCS report changes in vision or hearing. This can include blurred vision, ringing in the ears (tinnitus), or even temporary hearing loss.

9. Cognitive and Behavioral Changes:

  • DCS can affect cognitive functions and behavior. Some individuals experience confusion, memory problems, irritability, or altered mental states.

10. Paralysis or Weakness: – In severe cases of DCS, individuals may experience paralysis or extreme weakness in various parts of the body. This is a serious and potentially life-threatening symptom that requires immediate medical attention.

It’s important to note that the symptoms of decompression sickness can vary widely among individuals and may not always be present immediately after surfacing from a dive or experiencing pressure changes. Some symptoms may develop gradually over hours or even days, while others can be more acute.

If there is any suspicion of decompression sickness, it is essential to seek immediate medical attention. Delayed treatment can lead to worsening symptoms and complications. Hyperbaric oxygen therapy (HBOT) is the primary treatment for DCS, as it helps to reduce the size of gas bubbles in the body and promotes the elimination of excess nitrogen. Early intervention is critical to achieving a successful recovery and minimizing long-term effects.

Treatment for Decompression Sickness

Treatment for decompression sickness (DCS), often referred to as “the bends,” is a medical emergency that requires prompt and specialized care to alleviate symptoms, prevent complications, and promote recovery. DCS occurs when dissolved gases, primarily nitrogen, come out of solution in the body’s tissues and bloodstream due to rapid decompression, typically after ascending too quickly from deep water or high-pressure environments. Here’s an expanded overview of the treatment for decompression sickness:

1. Recognition and Diagnosis:

  • Immediate Evaluation: If there is any suspicion of DCS, seek medical attention immediately. Recognizing the symptoms and acknowledging the potential for DCS is crucial, as early intervention improves the chances of a successful recovery.
  • Medical Assessment: A healthcare provider will perform a thorough assessment, including a physical examination, a review of symptoms, and a dive history. The dive history helps determine the likelihood of DCS and the appropriate course of treatment.

2. Hyperbaric Oxygen Therapy (HBOT):

  • Primary Treatment: HBOT is the gold standard for treating DCS. It involves placing the affected individual in a hyperbaric chamber and exposing them to 100% oxygen at increased pressure. The goal is to:
    • Reduce the size of gas bubbles in the body.
    • Promote the elimination of excess nitrogen.
    • Deliver oxygen to oxygen-deprived tissues to aid in recovery.
  • Multiple Sessions: DCS treatment typically involves multiple sessions in the hyperbaric chamber. The duration and number of sessions depend on the severity of symptoms and the individual’s response to treatment.

3. Hydration:

  • Intravenous (IV) Fluids: To prevent or alleviate symptoms such as nausea, vomiting, and dehydration, individuals with DCS may receive IV fluids to maintain proper hydration.

4. Pain Management:

  • Analgesics: Pain medications may be administered to relieve joint and muscle pain associated with DCS.

5. Rest and Monitoring:

  • Observation: Individuals recovering from DCS require rest and continuous monitoring by medical professionals. Vital signs, neurological status, and overall condition are closely assessed.

6. Oxygen Therapy:

  • Normobaric Oxygen: In some cases, normobaric oxygen therapy (breathing 100% oxygen at sea-level pressure) may be used as a temporary measure before hyperbaric oxygen therapy is available. However, HBOT remains the preferred treatment.

7. Evacuation and Transport:

  • Transport to Hyperbaric Facility: In remote or maritime locations, individuals with DCS may need to be evacuated to a hyperbaric facility, which can provide specialized care. Timely transport is critical to initiating treatment.

8. Follow-Up Care:

  • Medical Evaluation: After treatment, individuals may require follow-up evaluations to assess their recovery and ensure there are no residual or delayed symptoms.

It’s important to emphasize that DCS is a medical emergency, and only trained medical professionals in hyperbaric medicine should administer treatment. Delayed or inadequate treatment can lead to worsening symptoms and complications, including permanent injury or death.

Preventing DCS is always the best approach. Divers and individuals exposed to rapid pressure changes should follow safe diving practices, including controlled ascents, proper decompression stops, and adherence to dive tables or computer algorithms. Maintaining proper hydration and fitness, avoiding alcohol and excessive caffeine before diving, and knowing one’s own dive limits are also essential steps to minimize the risk of DCS.

The Importance of Listening to Your Body

Freedivers must listen to their bodies. Being aware of personal limits and knowing when to abort a dive can prevent decompression sickness.

Myths About Freediving and Decompression Sickness

There are several misconceptions about freediving and decompression sickness. One common myth is that freedivers are immune to the bends. In reality, while the risk is lower, it is not entirely absent.


In conclusion, while the risk of decompression sickness in freediving is lower than in scuba diving, it is not negligible. Freedivers must follow safety protocols, including gradual ascents and safety stops, to minimize this risk. Safety should always be a top priority when exploring the depths, whether with a tank or simply holding one’s breath.


Q1: Can freedivers dive as deep as scuba divers without getting the bends? A: No, freedivers have depth limitations due to breath-holding, which reduces the risk but does not eliminate it.

Q2: What is the maximum depth for freediving to avoid decompression sickness? A: There is no specific depth limit, as it depends on factors such as dive duration and ascent rate. Safe freediving practices should always be followed.

Q3: How long should a freediver wait on the surface after a deep dive? A: Waiting times vary but typically range from one to several minutes, allowing for nitrogen off-gassing.

Q4: Are there any long-term effects of decompression sickness in freedivers? A: Prolonged or severe cases of decompression sickness can lead to permanent neurological or joint damage.

Q5: Is it safe to combine scuba diving and freediving on the same day? A: Combining these activities should be done cautiously, with attention to safety practices and surface intervals to minimize the risk of decompression sickness.


I hope you find this article informative. If you have any further questions or need any adjustments, please feel free to let me know!

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