Underwater Medicine- General Medicine/ Check Up, Maritime Medical Services

As divers spend longer periods submerged underwater, they are prone to several health conditions caused by the undersea environment.

Diving or Underwater Medicine is a field of medicine concerned with the diagnosis, treatment, and prevention of diving-related health conditions.

Although advancements in technology ensure the safety and reliability of diving equipment, there is still a risk of diving injuries ranging from decompression sickness to arterial gas embolism and barotrauma.

Today, underwater medicine treats various hyperbaric conditions through Hyperbaric Oxygen Therapy, an advanced treatment for healing illnesses associated with underwater diving.

Keep reading to learn more about Diving Medicine, common diving illnesses, and the treatment for most diving-related conditions.

What Is Underwater Medicine?

Underwater medicine or diving medicine is more commonly known as Undersea And Hyperbaric Medicine (UHM). It’s a branch of sports and occupational medicine that studies and treats different conditions caused by the long-term exposure of the human body to abnormal surrounding pressure.

Hyperbaric conditions are illnesses caused by the effect of pressure changes in gas underwater. The increased pressure around your body as you’re diving can affect your organ function and lead to adverse effects.

Hyperbaric medicine treats hyperbaric conditions, such as:

  • Arterial gas embolism
  • Gas gangrene - gas collecting in your tissues
  • Carbon monoxide poisoning
  • Injury from crushing
  • Decompression sickness

Undersea medicine also ensures that a diver is physically and psychologically fit before scuba diving.

Which Doctor Treats Diving Accidents?

A Diving Physician, commonly known as a Dive Doctor, is a licensed physician specializing in diagnosing, treating, and preventing diving-related health conditions.

A diving physician has completed various courses for hyperbaric medicine as “physicians training in diving medicine” and is certified by the Diving Medical Advisory Committee (DMAC).

DMAC certified diving physicians are trained in:

  • Diving medical, medical assessment of divers
  • Medical management of diving accidents and illnesses

What Conditions Does Underwater Medicine Cover?

Today, statistics estimate around 6 million people around the world are certified divers. With the number of divers steadily increasing, so do the chances of underwater accidents.

According to Divers Alert Network (DAN) reports, most fatalities related to diving are because of drowning and other underwater conditions like cardiovascular diseases and arterial gas embolism.

Let’s take a look at the different diving accidents and conditions that hyperbaric medicine covers.

Decompression Illness or Dysbarism

Dysbarism is any medical condition that results from changes in ambient pressure or surrounding pressure. Decompression illnesses arise when this pressure change occurs too fast, and your body cannot adjust.

These are a few decompression illnesses that underwater medicine treats:

  • Decompression Sickness
  • Arterial Gas Embolism
  • Barotrauma

Decompression Sickness

Decompression sickness is a common injury among deep-sea and scuba divers, wherein bubbles form in and around their blood vessels (intra- and extravascular bubble formation) during ascent.

When you dive deep into the water, the pressure increases around and within your body. Certain gases like oxygen and nitrogen liquify and seep into your tissue. When you ascend too quickly, these elements return to their gaseous form and expand inside your tissue, causing bubble formation.

Decompression sickness can also damage the lining of your heart and blood vessels and stimulate inflammation.

The expansion of bubbles also damages the surrounding tissues and organs, causing adverse side effects.

  • Numbness
  • Pain
  • Dizziness
  • Fatigue
  • Weakness
  • Seizure
  • Altered mental state

Diving physicians treat decompression sickness through recompression therapy or hyperbaric oxygen therapy (HBOT). In recompression therapy, your physician places you in a sealed chamber to breathe in pure oxygen at a higher pressure level. This pushes the gases back into a fluid state. The pressure is then gradually normalized.

Hyperbaric oxygen therapy is approved for various conditions, ranging from bone disease to burns. In undersea medicine, HBOT aims to:

  • Decrease the bubble size
  • Improve blood circulation to tissues
  • Increase nitrogen washout
  • Decrease carbon monoxide concentration

Arterial Gas Embolism

Arterial gas embolism (AGE) is a potentially life-threatening event wherein gas bubbles enter or form in your arteries when diving, blocking the blood flow and resulting in organ ischemia. Organ ischemia is organ damage because of decreased blood and oxygen in your tissues.

AGE is the most common cause of death among divers. A diver may develop an arterial air embolism when they:

  • Ascend water too quickly
  • Spend too long underwater
  • Hold their breath while coming to the surface

The lack of circulation can cause central nervous system ischemia, stroke, or heart attack. Symptoms of AGE can develop rapidly, taking about 10-20 minutes to develop.

A diver may have arterial gas embolism if they experience:

  • Altered mental status
  • Loss of consciousness
  • Seizures
  • Shock
  • Difficulty in breathing
  • Loss of movement on one side of the body
  • Joint pain or muscle pain
  • Low blood pressure
  • Blurred vision

As soon as you notice symptoms of arterial gas embolism, seek medical attention from a diving medicine specialist immediately.

Treatment for AGE typically involves recompression therapy or hyperbaric oxygen therapy. In HBOT, you breathe in pure oxygen to reduce the size of gas bubbles and improve blood circulation to your tissues.


Barotrauma occurs when abrupt changes in pressure compress or expand gas trapped in your body. When you dive underwater, the pressure becomes considerably heavier. As you dive deeper, the change in pressure increases drastically, resulting in gas bubbles in structures like your ear, sinuses, and lungs.

Barotrauma is a painful condition that may cause tissue damage, such as

  • Damage to the eardrum
  • Damage in the middle ear
  • Damage in the inner ear
  • Sinus Squeeze - irritation of the lining of nasal sinuses
  • Lung squeeze - compression of the lungs and chest cavity

Ear barotrauma is the most common illness of diving, causing severe ear discomfort due to pressure changes. The formation of a gas bubble blocks the Eustachian tube, which connects your ear to your throat and nose and helps regulate ear pressure.

If you are diving and experience the following signs and symptoms, you may have barotrauma:

  • Severe pain in the ear canal
  • Bleeding from ear
  • Ringing in the ear
  • Dizziness
  • Vomiting and nausea
  • Nasal bleeding
  • Chest pain
  • Cough

Undersea medicine treatment for barotrauma depends on the location of the gas formation.

  • External Ear Barotrauma: Your diving physician may recommend steroid drops and topical analgesics to reduce the congestion around the Eustachian tube opening, a narrow passage leading from your pharynx to the cavity of the middle ear.
  • Middle Ear Barotrauma: Topical decongestants relieve symptoms of congestion and improve airflow in your middle ear. If you develop an infection, your dive doctor will prescribe antibiotics.
  • Inner Ear Barotrauma: Your physician can prescribe steroids to reduce inflammation in your inner ear.
  • Sinus Barotrauma: Saline irrigations, decongestants, and topical corticosteroids are prescribed to minimize congestion and open blocked sinus passages.
  • Pulmonary Barotrauma: Air in the center of your chest usually resolves within hours to days with no treatment. Your physician may suggest hyperbaric oxygen therapy for pulmonary barotrauma. Exposure to pure oxygen may speed up the resorption of gas in your tissues.

Cardiovascular Diseases

Cardiovascular diseases are the second cause of death among scuba divers but the first cause of disabling injury.

Coronary disease screening is a priority when divers undergo a diving medical test. Recreational divers are at a higher risk of diving injury due to cardiovascular disease because of risk factors like age, high blood pressure, smoking, and high cholesterol. 

In people at risk, diving can contribute to developing cardiovascular diseases by:

  • Hypertension or high blood pressure
  • Decreased systemic oxygen supply
  • Bradycardia, slow heart rate
  • Increased heart muscle oxygen demand
  • Overworking the heart

If you have a cardiovascular disease and get treatment, you can return to diving if you show exercise tolerance and do not show any signs of arrhythmias during physical activity.

What Is The Treatment For Diving-Related Conditions?

Hyperbaric Oxygen Therapy (HBOT) is the most commonly used treatment of diving illnesses, such as decompression sickness.

In HBOT, you are placed in a pressurized chamber where you’ll breathe in pure oxygen. The air pressure in the chamber is increased 2 to 3 times higher than the average air pressure, allowing your lungs to take in more oxygen.

HBOT aims to decrease gas bubble formation, improve blood supply to your tissues, and regulate the gas concentration in your body.

Hyperbaric oxygen therapy is the first line of treatment in several hyperbaric conditions, such as

  • Decompression sickness
  • Arterial gas embolism
  • Carbon monoxide poisoning
  • Tissue gangrene

Frequently Asked Questions (FAQs)

What does diving do to your body? Diving can significantly impact your body and overall physical health. The increased levels of ambient pressure underwater can adversely affect your heart and circulatory system. Your baroreceptors sense pressure changes and signal your brain to regulate your body functions.

How do I become a dive doctor? Physicians training in diving medicine must undergo extensive courses in underwater medicine and training in diving. Prospective diving physicians usually need to have a medical degree, license to practice medicine, and at least 1-year internship or experience relevant to the field.

How much does a dive medical cost? There are 2 types of diving medical examinations: recreational and commercial. The cost depends on your location. In the United States, a dive medical exam can cost about $132-$176. A dive medical exam usually includes a questionnaire, blood pressure, height, weight, hearing and eyesight tests, urine tests, and lung function tests.

What does a dive med-tech do? A diving medical technician or a dive med-tech ensures the safety of your entire diving team. They identify hazards, attend to divers’ needs, assess them, and execute underwater emergency responses. A diving medical technician is trained in various treatments for diving conditions and is always ready for any medical emergency.

Can any doctor do a dive medical? Any GP can perform a dive medical, but if they do not have the right equipment, they may refer you to a dive physician certified by the DMAC in diving medicine.


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About the Author:
Dr. Mersad is a medical doctor, author, and editor based in Germany. He's managed to publish several research papers early in his career. He is passionate about spreading medical knowledge. Thus, he spends a big portion of his time writing educational articles for everyone to learn.