Skip to content

What Medical Conditions Prevent You from Scuba Diving? Everything You Need to Know

Scuba diving is undoubtedly an enjoyable activity that allows you to explore the underwater world and witness the beauty of marine life. However, it’s important to remember that diving carries inherent risks. To ensure your safety and that of those around you, it’s essential to have a healthy body and mind before diving.

Scuba Diving doesn’t need you to have an athletic physique but indulging in this activity does require you to be physically and medically fit enough to be able to dive and carry yourself safely underwater.

Photo by Robina Weermeijer on Unsplash

Before participating in this sport, you should be aware of any underlying medical conditions that may pose a risk. Medical conditions can affect your body’s response to changes in pressure, oxygen levels, and physical exertion, which can all impact your ability to dive safely. Some medical conditions pose a severe threat to diving while others are generally moderately risky but can be regulated with proper medications.

For example, let’s say you have a history of heart disease or high blood pressure. During a dive, you’ll be exposed to physical exertion and pressure changes that can put stress on your cardiovascular system. If you have an underlying cardiovascular condition, such as arrhythmia or coronary artery disease, you may be at a higher risk of experiencing a heart attack or stroke while diving. That’s why it’s crucial to consult a diving physician who can evaluate your cardiovascular health and determine if you are fit to dive.

I have gathered a list of all known medical conditions that inherently pose a risk to diving in this article. I have categorized all the diseases based on the level of risk they pose.

List of Medical Conditions that Poses a Risk to Scuba Diving

1. Behavioral Health

According to a study published in the Journal of Psychiatric Research, up to 30% of recreational scuba divers may experience anxiety or panic underwater.

A calm and focused mind is essential for scuba diving. Any mental health condition that may interfere with an individual’s ability to stay calm and focused can be potentially dangerous.

For example, panic attacks or severe anxiety can cause a person to hyperventilate, leading to an increased risk of decompression sickness (DCS). Therefore, individuals with certain behavioural health conditions may require clearance from a diving physician before participating in scuba diving.

Severe Risk

  • Panic disorder with or without agoraphobia
  • Claustrophobia
  • Psychosis
  • Bipolar disorder
  • Severe anxiety or depression
  • Substance abuse or dependence

Moderate Risk

  • Attention Deficit Hyperactivity Disorder (ADHD)
  • Obsessive-compulsive disorder (OCD)
  • Eating disorders
  • Mild to moderate anxiety or depression

2. Cardiovascular

Scuba diving requires physical exertion and exposure to pressure changes, which can put stress on the cardiovascular system. Any underlying cardiovascular condition can increase the risk of decompression sickness or pulmonary edema during a dive. Therefore, individuals with certain cardiovascular conditions must be evaluated by a diving physician to determine if they are fit to scuba dive.

It is estimated that over 30% of scuba diving fatalities are related to cardiovascular issues and involve mostly people over 50. Cardiovascular diseases such as hypertension, coronary artery disease, and arrhythmia can pose a significant risk during a dive.

Severe risk

  • Coronary artery disease (CAD)
  • Hypertrophic cardiomyopathy
  • Congestive heart failure
  • History of heart attack or stroke
  • Aortic aneurysm

Moderate risk

  • Valvular heart disease
  • Hypertension (controlled)
  • Pacemaker
  • Heart murmur

3. Neurological

The neurological system plays a crucial role in maintaining balance and coordination, which are essential for scuba diving.

Certain neurological conditions, such as epilepsy or Parkinson’s disease, can increase the risk of seizures or loss of consciousness, which can be potentially hazardous during a dive.

Severe risk

  • Epilepsy or seizures
  • Stroke
  • Multiple sclerosis
  • Parkinson’s disease
  • Brain injury

Moderate risk

  • Migraine headaches
  • History of seizures (controlled)
  • Vertigo
  • Bell’s palsy

4. Pulmonary

The lungs are directly exposed to the pressure changes that occur during scuba diving. The American Lung Association reports that approximately 25 million Americans have asthma, a chronic respiratory disease that can make breathing difficult. Diving requires controlled breathing, and individuals with asthma may experience difficulty breathing underwater, which can lead to a medical emergency.

Any underlying pulmonary condition such as chronic obstructive pulmonary disease (COPD), asthma (uncontrolled), pulmonary fibrosis, and cystic fibrosis can increase the risk of pulmonary barotrauma, which can be potentially fatal. This condition can cause chest pain, shortness of breath, coughing, and other symptoms, and can even lead to a collapsed lung or other serious complications.

Severe risk

  • Chronic obstructive pulmonary disease (COPD)
  • Pulmonary fibrosis
  • Pneumothorax
  • Cystic fibrosis
  • Asthma (uncontrolled)

Moderate risk

  • Asthma (controlled)
  • Sinusitis
  • Bronchitis

5. Gastrointestinal

Gastrointestinal conditions can affect an individual’s ability to equalize pressure changes during a dive, increasing the risk of ear or sinus injuries. In addition, certain gastrointestinal conditions, such as inflammatory bowel disease or gastric ulcers, can cause abdominal pain or discomfort, which can affect a person’s ability to focus and remain calm during a dive.

Talking about gastric problems have you ever wondered if it is safe to pass gas frequently while scuba diving? Maybe you should check out this article about the myth vs. reality of farting during your dive.

According to the National Institute of Diabetes and Digestive and Kidney Diseases, over 60 million Americans experience acid reflux symptoms at least once a month. Acid reflux can be exacerbated during a dive due to the pressure changes in the stomach, which can lead to severe discomfort and even vomiting underwater.

Severe risk

  • Inflammatory bowel disease (IBD)
  • Gastric ulcer
  • Hernia
  • Severe acid reflux or GERD
  • Bowel obstruction

Moderate risk

  • Mild acid reflux or GERD
  • Irritable bowel syndrome (IBS)

6. Haematological

Certain haematological conditions like anaemia, polycythemia, and thalassemia can affect blood clotting or oxygen-carrying capacity, increasing the risk of decompression sickness or other diving-related injuries.

Sickle cell anaemia, for example, can cause blood cells to become sickle-shaped, making them more prone to clotting, which can block small blood vessels and lead to tissue damage, including in the lungs. Bleeding disorders can cause excessive bleeding from even minor injuries, increasing the risk of bleeding complications during decompression. Blood clotting disorders, on the other hand, can increase the risk of blood clots forming in the body, which can become dislodged during diving and cause serious complications.

Severe risk

  • Sickle cell anaemia
  • Bleeding disorders (e.g. haemophilia)
  • Blood clotting disorders (e.g. deep vein thrombosis)

Moderate risk

  • Anaemia
  • Polycythemia
  • Thalassemia

7. Metabolic & Endocrinological

Metabolic and endocrinological conditions, such as diabetes or thyroid disorders, can affect an individual’s ability to regulate blood sugar or hormone levels during a dive, increasing the risk of decompression sickness or other diving-related injuries.

Severe risk

  • Diabetes (insulin-dependent)
  • Thyroid disease (uncontrolled)
  • Adrenal gland disorders
  • Pituitary gland disorders
  • Cushing’s syndrome

Moderate risk

  • Type 2 diabetes (controlled)
  • Hypothyroidism
  • Hyperthyroidism

8. Orthopaedic

Scuba diving requires a certain level of physical fitness and mobility, as well as the ability to carry heavy equipment. Any underlying orthopaedic condition, such as a recent joint replacement or chronic pain, can affect an individual’s ability to move freely and safely during a dive.

Severe risk

  • Spinal cord injury
  • Joint replacement (recent)
  • Severe osteoporosis
  • Recent fractures or dislocations
  • Chronic pain

Moderate risk

  • Arthritis
  • Mild to moderate osteoporosis
  • Mild back pain

9. Otolaryngological

The ears, nose, and throat are directly exposed to the pressure changes that occur during scuba diving. During a dive, pressure changes can affect the ears and sinuses, leading to discomfort or even damage to the inner ear.

Any underlying otolaryngological condition, such as hearing loss or chronic ear infections, can increase the risk of ear or sinus injuries. Hearing loss can make it difficult to equalize pressure in the middle ear, which can lead to barotrauma. Chronic ear infections can lead to eardrum perforation, and diving can increase the risk of such injuries.

Additionally, if you’ve had any surgery in the ears or nose, such as sinus surgery or cochlear implantation, it will need time to heal before you can safely dive.

Severe risk

  • Hearing loss (unilateral or bilateral)
  • Tinnitus
  • Meniere’s disease
  • Recent ear surgery
  • Chronic ear infections

Moderate risk

  • Allergies (seasonal or food-related)
  • Sinus infections

Consulting a Dive Doctor Regularly: Why Its so Important

Consulting a dive doctor before scuba diving is crucial, especially if you have any underlying medical conditions. A dive doctor is the best suited for assessing your medical history and current health status to determine if scuba diving is safe for you. They can also provide recommendations for any necessary precautions or adjustments to your dive plan to ensure your safety underwater.

Moreover, it is important to be honest and open about any medical conditions you may have when filling out the medical form that dive centers provide. Concealing any medical conditions can put yourself and others at risk during the dive.


Scuba diving is an exciting and exhilarating activity that allows us to explore the wonders of the underwater world. However, it’s important to remember that not everyone is suited for this activity, especially those with certain medical conditions. Knowing which medical conditions can prevent you from scuba diving is crucial for your safety and the safety of others.

As with any physical activity, it’s always best to consult with a medical professional before diving into the deep blue sea. So, whether you’re a seasoned diver or a beginner, make sure to prioritize your health and safety first.


William Dupre

Retired Master Diver with 20+ years of experience and 2100+ logged dives. Presently, spending my time blogging about Diving and checking off locations one by one from my bucket list of dive destinations.

Leave a Reply

Your email address will not be published. Required fields are marked *