Find Out Medical Conditions That Might Stop You From Scuba Diving

Find Out Medical Conditions That Might Stop You From Scuba Diving

Scuba diving in the beautiful marine is pretty safe compared to most extreme sports. And the security gear is even safer than skydiving’s double safety mechanism.

There’s one caveat, though – while injuries are rare in scuba diving, the sheer atmospheric pressure and loads of other physics-related stuff interacting with your body in deep waters can be uncomfortable for an unhealthy person.

In layman’s terms, scuba diving is a physically and mentally strenuous activity that isn’t for everyone. I’ll explain in detail – then we’ll discuss common medical conditions that prevent you from doing scuba.

What makes scuba diving different from other extreme sports?

According to the 2020 study, Medical Examination of the Recreational SCUBA Diver, “SCUBA diving is an enjoyable and safe sport when it is pursued by healthy, well-trained, disciplined and well-equipped individuals who are comfortable in the water. Since the sport diver is out for recreation, there is no need to take chances or shortcuts with any of these factors.”

Scuba diving is one of the most demanding sports for an unhealthy person because of one factor – water is denser than air. You can get away with a slight error with skydiving and other “above ground” extreme sports, but not with scuba diving.

In scuba diving, your body faces more pressure and exhaustion the deeper you go below sea level. Even with a full oxygen tank, your body deals with various forces like changing atmospheric pressure, which takes a massive toll on your inner ears and lungs.

That said, a relatively healthy human body can easily withstand most of these phenomena. Where exactly do we draw the line for the eligibility criteria?

Who should not go scuba diving?

People with medical issues related to lungs, heart, and brain should not go technical diving. Common conditions include asthma, cardiovascular diseases, pneumothorax, seizures, and diabetes. They may get away with recreational scuba diving if the issues are mild.

Medical Conditions That Stop You From Scuba Diving

Dozens of medical conditions could potentially stop you from scuba diving or other sports. The human body is complicated. So, to make this influx of information easy for you, I’ve categorized the conditions into eight sections.

1. Neurological Problems

People with neurological problems, especially the spinal cord or the peripheral nerves connecting the spinal cord to the brain, aren’t allowed scuba diving. Individuals with a history of seizures also fall in this category.

What medical conditions can stop you from scuba diving?

Spinal Cord

The strictness of these policies is subjective and varies among different locations. Some scuba diving instructors won’t allow you to dive even if you have a clearance certificate from a medical professional.

Scuba diving is not allowed for a person suffering from epilepsy. If you have been off medication and without a seizure for over 5 years, you might be considered fit to dive. For patients with nocturnal seizures, you have to be off medication for at least 3 years.

These strict rules are enforced because you can potentially have a seizure at any time, even if the possibility is super low.

Major Neurological Conditions:

  • Seizures (less than 5 years)
  • Epilepsy
  • Multiple Sclerosis
  • Paralysis
  • Cerebrovascular insufficiency
  • Parkinson’s Disease
  • Aneurysm
  • TIA strokes

2. Cardiovascular (Heart) Problems

Scuba diving is no walk in the park – the change in pressure not only affects your lungs (breathing) but also your heart (blood pressure). Diving can be difficult if you have high blood pressure or other cardiovascular problems.

For example, you can’t scuba dive if you have persistent hypertension, chest pains, and palpitations in addition to high blood pressure. A medical clearance certificate is almost always required in these situations. You can also get the certificate as a precautionary step if you have had cases of heart murmur and premature death in the direct family.

As for the hematological problems, you need to be careful as it increases the chances of getting decompression illness (DCI). It’s recommended to wait 6 months to a year after a heart attack or heart surgery before scuba diving.

Major Cardiovascular Conditions:

  • Coronary artery/heart disease
  • Cardiomyopathy
  • Chronic immersion pulmonary edema
  • High blood pressure
  • Implanted cardiac defibrillator
  • Pulmonary hypertension

More minor conditions include using a pacemaker and a single isolated case of pulmonary edema. Hematological problems include chronic anemia.

3. Mental Health & Behavioural Problems

This one is quite tricky because diagnosing behavioral and other mental health problems aren’t cut and dry. Additionally, you won’t be barred from having just about any random mental health condition.

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The issue is the seriousness of the problem because that directly correlates to your medication. For example, you should NOT take psychotropic medications while scuba diving. If so, you’ll need medical clearance from a psychiatrist.

What medical conditions can stop you from scuba diving?

Scuba Diving can feel claustrophobic

As I said, these conditions don’t matter as much as their intensity does since so many of these are very hard to evaluate for a scuba diving situation.

For instance, if you have severe depression, bipolar disorder, or psychosis, you might get medical clearance to scuba dive, but it may put your well-being at high risk.

Major Mental Health Conditions:

  • Psychosis
  • Bipolar Disorder
  • Severe Depression
  • Panic Attacks
  • Severe issues of drug and alcohol abuse
  • Claustrophobia/agoraphobia

4. Respiratory & Pulmonary Problems

You shouldn’t go scuba diving if you have asthma, as the conditions that might lead to an asthma attack are inherent to scuba diving. These attacks can tighten the airflow by constricting the muscles, which isn’t ideal underwater because it can lead to drowning.

Other pulmonary ailments are just as dangerous because they place a tremendous toll on your lungs and other parts of the respiratory system. This strain can often result in pulmonary over-inflation and alveolar ruptures – both of which can be fatal underwater.

An alveolar rupture is dangerous because it can accidentally bypass air in the bloodstream, leading to an arterial gas embolism (AGE). And an embolism like that underwater is the recipe for a stroke attack.

Major Respiratory Conditions:

  • Pneumothorax
  • Pulmonary hypertension
  • Asthma
  • Thoracic surgery
  • Lung disease

5. Gastrointestinal & Metabolic Problems

It might sound far-fetched, but diabetes can prevent you from scuba diving. Severely diabetic or obese (BMI above 30) individuals usually can’t scuba dive in the United States because it can be fatal if your blood sugar levels are off.

Also, gastrointestinal problems / conditions are an absolute NO for scuba diving. Any gastrointestinal condition that leads to acid reflux, vomiting, perforation, and diarrhea will immediately get you off the boat – and for good reason because even one of these outcomes is enough to drown you.

Ps…pregnancy also prevents you from scuba diving.

6. Cancer Problems

You should not attempt scuba diving while on chemotherapy because chemo and radiation therapy are exhausting and bring your stamina levels to zero. Ideally, wait until after you’re fully recovered from the effects of your therapy.

Since cancer isn’t an exact problem, the scuba restrictions are variable as well. People with brain, lung, or colon cancer MIGHT have to leave scuba diving forever. Comparatively, individuals with other cancer types only require a medical clearance certificate to dive, provided that they’re healthy and have enough stamina.

7. Other Miscellaneous Problems

Musculoskeletal problems such as amputated legs and scoliosis can prevent you from scuba diving because you need the ability to move around, especially in colder waters with such heavy gear. Other such issues include disc prolapse, aseptic necrosis, and severe back pain.

You also need to be otolaryngological healthy to scuba dive. Since inner ears are inflexible like solids, they’re susceptible to rupturing as you go deeper. It’s also why you shouldn’t take scuba dives until sometime after inner ear surgery.

What should you not do after scuba diving?

As long as we’re on the topic of preventing scuba mishaps, here are the things you should not do after scuba diving.

1. Don’t go mountain climbing, skydiving, or other such activities

You must know by now that change in altitude has varying yet astounding impacts. Mountain climbing in the first 24 hours of scuba diving can even result in decompression sickness.

The same goes for skydiving, zip-lining, and related activities. Stick to the ground for the first 24 hours and avoid changing the elevation further. Although, you can skydive (and mountain climb, etc.) prior to scuba diving.

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2. Don’t consume alcohol

Avoid alcohol (or at least don’t drink heavily) during the first 24 hours. Avoid any activity that causes dehydration because it also leads to decompression sickness.

3. Avoid massages right after diving

You may want that relaxing massage after a tiresome day of scuba diving. Still, you should ideally avoid it for the first 24 hours. And if you can’t avoid it, just get the normal one – deep tissue massages should be avoided at all costs. Deep tissue massages can mask the symptoms of decompression sickness and lead to a misdiagnosis.

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I got into extreme sports about 20 years ago and am a die-hard adrenaline junkie. Just like in business, I choose my outdoor adventures based on how much they scare me. My goal is to share the lessons I’ve learned over the past couple of decades braving the unknown to encourage you to do the same.


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Elevated Adventurer is your go-to sherpa for all things adventure sports and outdoor exploration. Here you’ll learn everything you need to know about your favorite outdoor sports from rock climbing and scuba to skydiving and extreme sports.

Is Scuba Diving Safe?

Scuba diver at Ginnie Spring Cave, Florida, USA

Natalie Gibb owns a dive shop in Mexico and is a PADI-certified open water scuba instructor and TDI-certified full cave diving instructor.

Is scuba diving dangerous? As with any adventure sport, some risk is involved. Humans are not built to breathe underwater, which means that a diver is completely dependent upon the proper equipment, skills, and emergency training to ensure a safe resurface for every dive. This truth, while it may sound frightening, should not discourage prospective divers. However, it should encourage divers to approach the sport with an appropriate amount of respect. Scuba diving is not dangerous as long as a diver seeks thorough training, follows safe diving guidelines, uses proper gear, and dives within his experience level.

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How Likely Are You to Die Scuba Diving?

Let’s cut to the chase and answer the biggest, scariest question first: How likely are you to die scuba diving? According to the “Diver’s Alert Network (DAN) 2010 Diving Fatalities Workshop Report”, a diving fatality occurs in 1 out of every 211,864 dives. Whether this seems risky to you or not is a matter of personal opinion, but let’s put this number in perspective by looking at the fatality rates of some other activities.

The Risks of Scuba Diving in Comparison With Other Activities

1 out of every 211,864 dives ending in fatality doesn’t seem so great a number when compared with the fatality rates of other activities. For example:

• 1 out of every 5,555 of registered drivers in the US died in car accidents in 2008 (
• 1 out of every 7692 pregnant women died from pregnancy complications in 2004 (National Center for Health Statistics).
• 1 out of every 116,666 skydives ended in a fatality in 2000 (United States Parachuting Association).
• 1 out of every 126,626 marathon runners died of sudden cardiac arrest while running a marathon between 1975-2003 (National Safety Council)

Statistically, diving is safer than driving, having a kid, skydiving, or running a marathon. Of course, this is a generalization. All the dates are from different years, and we’re talking about diving fatalities, not injuries. Our goal is simply to lend some perspective to the diving statistic. When we consider why divers die, we discover that for a responsible diver who seeks training and dives within his limits, the risks of diving are even lower.

Most Common Factors Contributing to Diver Fatalities

The top three root causes leading to diver fatalities (DAN Diving Fatalities Workshop Report) are:

1. Pre-existing disease or pathology in the diver
2. Poor buoyancy control
3. Rapid ascent/violent water movement

All three of these are completely avoidable. In fact, if a diver respects the safe diving practices taught during scuba diver training, none of these factors should be a problem. For example:

Before beginning dive training, prospective scuba divers are given a scuba diving medical questionnaire, which, if answered truthfully, should bring up any medical problems that could predispose a diver to injury or death, such as lung diseases or heart issues. Of course, some divers do lie on these medical release forms and ignore the warning not to dive with contraindicated conditions. Furthermore, a diver may develop a medical condition that is contraindicated for diving after certification. Review the scuba diving medical questionnaire periodically and take it seriously, even after becoming a certified diver.

Poor buoyancy control is an issue with many divers. Who to blame for this issue is debatable – the divers who have poor buoyancy control or the instructors who certified them. In either case plenty of certified divers no longer (or never did) understand how a buoyancy compensator (BC) works or how pressure changes on descent and ascent affect buoyancy. If this subject is unclear, or if a diver simply hasn’t developed the physical ability to control his buoyancy properly, he needs practice and a scuba diving refresher course before attempting to dive again.

Rapid ascents are frequently due to poor buoyancy control. In some cases, divers simply panic and rocket to the surface. This is simply unacceptable. If water in a diver’s mask makes him panic, he should practice flooding and clearing his mask in a pool until it becomes routine. If a buddy constantly strays so far that he is impossible to alert in an out-of-air emergency, get a new buddy. A diver who checks his pressure gauge and surfaces with a reasonable reserve of air in his tank is unlikely to run out of air. If the water is so rough that water movement is going to be an issue, don’t dive or end a dive the moment the difficult current/surge/chop is experienced.

DAN’s report goes on to explain that some of the leading contributing factors to diver fatalities are buddy separation and inadequate training for the dive being attempted. Both of these are violations of the standard safe diving guidelines.

Common Diving Illnesses

Some of the most common diving-related illnesses are ear barotrauma, decompression sickness, and pulmonary barotrauma, but these conditions can usually be avoided with proper training and preparation.

The Take-Home Message About Scuba Diving Risks

Is scuba diving dangerous? It all depends upon a diver’s attitude. Divers who treat their scuba training as a “do it once and be done” course and fail to review dive theory and practice basic scuba skills after periods of diving inactivity (and I mean after a short period of diving inactivity, such as 6 months) are more at risk of a diving injury that divers who keep their skills current. Similarly, divers who embark on dives that are beyond the parameters of their training level are also at a higher risk than divers who take their training limitations seriously. For example, most open water certifications qualify a diver to go down to 60 feet, no deeper. If a diver wants to go deeper, there are courses for that — he should take one! For divers who approach diving with an attitude of respect and conservatism, the risks of diving are minimal.

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Top 3 Reported Diving Illnesses and Injuries

Scuba diving accidents are rare, but they do happen. Knowing how to recognize and appropriately respond to diving injuries may benefit you or someone you care about.

The most common issues reported via email and Divers Alert Network’s Emergency Hotline are ear and pulmonary barotrauma, decompression sickness and marine envenomation.

1. Ear and Pulmonary Barotrauma

  • Ears feel “full” or like they have water in them
  • Severe ear pain
  • Dizziness, vertigo, nausea
  • Muffled hearing, hearing loss, ringing in the ear
  • Red or swollen external ear
  • Blood or fluid oozing from ear
  • Pain when swallowing

If you or another diver experience any of the following symptoms, stop diving and seek medical care – ideally from an ear nose and throat specialist. After ruling out an infection, the doctor may recommend nasal steroid sprays, acetaminophen, ibuprofen, a hot compress or oral decongestants like pseudoephedrine.

Avoid ear barotrauma by equalizing early and often. Never force your descent and avoid using decongestants.

Pulmonary barotrauma is a lung overexpansion injury that typically occurs when a diver fails to exhale properly, or holds their breath during ascent. Compressed gas in the lungs expands as the diver ascends and can cause the lungs to rupture if not exhaled. The lungs don’t feel pain like other parts of the body, so a barotrauma can occur with little warning.

Serious medical conditions can occur as the result of pulmonary barotrauma including: mediastinal emphysema, subcutaneous emphysema, pneumothorax and arterial gas embolism. This is why the number one rule of scuba diving is to breathe continuously and never hold your breath!

Uncontrolled or panicked assents frequently precede a pulmonary barotrauma. Should you find yourself making a rapid ascent, try to make a continuous “aaaaah” sound while exhaling. This can reduce the chances of a lung injury. The best prevention is a slow ascent from every dive. In addition, do not dive with any symptoms of a chest cold or other respiratory illness. Develop and maintain proper buoyancy skills. Divers who feel chest pain, difficulty speaking, or discomfort with swallowing after a dive should NOT resume diving as these are potential signs of pulmonary barotrauma. The diver should immediately seek professional medical care.

2. Decompression Sickness (aka The Bends)

Decompression sickness describes injuries resulting from a rapid decrease in surrounding pressure. Nitrogen absorbed by the body at depth comes out of solution and forms bubbles in body tissues and the bloodstream.

DCS occurs most often when a diver pushes depth and time limits, but it can occur without obvious cause. For example: flying in a commercial airplane that experiences a sudden loss of pressure or flying too soon after diving can cause DCS because the cabin pressure is less than the pressure at sea level. This doesn’t happen frequently, but it is a known cause.

Symptoms of DCS may include: skin rash, itching, joint pain, dizziness, fatigue, and bladder problems. These symptoms usually occur within one hour after surfacing, but can be delayed up to 24 hours.

Denial is arguably the worst “symptom” of DCS as the sooner DCS is treated, the more likely it is the diver will make a full recovery. Oxygen first aid is essential and may reduce symptoms; however, O2 is not a substitute for a full evaluation by a medical professional. Always contact DAN or a dive physician if signs of DCS are observed – even if they’ve diminished.

3. Marine Envenomation

Many marine animals use toxins for self-defense or for prey capture. Envenomation occurs when direct contact is made and the venom or toxin is injected by bite, puncture or sting.

Injuries typically occur as divers are entering or exiting the water, but they can also happen when a diver accidentally or deliberately attempts to handle an animal. Envenomations usually cause itching, burning, or other irritation. Rarely do life-threatening reactions occur.

Coral scrapes are perhaps the most common marine life-related injury experienced by divers and snorkelers. Cuts and scrapes from coral and barnacles can fester like a cat scratch – taking weeks or even months to heal without proper treatment. Spine punctures and stings are another common marine life injury.

  1. Carefully remove the spine or stinger (not recommended for stingray spines)
  2. Immerse the wound in non-scalding hot water: 110 – 113 F / 43.3 – 45 C (to tolerance)

DAN encourages divers of all levels to get first-aid training and be prepared to respond to diving injuries, including first aid for marine life injuries. However, if the injured diver is weak, vomiting, short of breath, or acts intoxicated, seek immediate medical care.

Most diving injuries are preventable. Breathe constantly, equalize regularly, and avoid contact with marine life, and ascend slowly. Help a fellow diver avoid injury by sharing this article and join DAN to support dive safety research and 24-7 emergency medical assistance for divers worldwide.

The information above is for informational purposes only and is in no way meant to take the place of skilled medical care. No article can give you the same degree of information as an experienced medical practitioner.




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