Diving medicine, also called undersea and hyperbaric medicine (UHB), is the diagnosis, treatment and prevention of conditions caused by humans entering the undersea environment. It includes the effects on the body of pressure on gases, the diagnosis and treatment of conditions caused by marine hazards and how relationships of a diver's fitness to dive affect a diver's safety.

Hyperbaric medicine is a corollary field associated with diving, since recompression in a hyperbaric chamber is used as a treatment for two of the most significant diving related illnesses, decompression illness

Decompression illness

Decompression Illness describes a collection of symptoms arising from decompression of the body.DCI is caused by two different mechanisms, which result in overlapping sets of symptoms. The two mechanisms are:...

 and arterial gas embolism.

Effects of depth and pressure

Most diving accidents or illnesses are related to the effect of depth/pressure on gases in the body; examples are decompression sickness

Decompression sickness

Decompression sickness describes a condition arising from dissolved gases coming out of solution into bubbles inside the body on depressurization...

, nitrogen narcosis

Nitrogen narcosis

Narcosis while diving , is a reversible alteration in consciousness that occurs while scuba diving at depth. The Greek word ναρκωσις is derived from narke, "temporary decline or loss of senses and movement, numbness", a term used by Homer and Hippocrates...

, oxygen toxicity

Oxygen toxicity

Oxygen toxicity is a condition resulting from the harmful effects of breathing molecular oxygen at elevated partial pressures. It is also known as oxygen toxicity syndrome, oxygen intoxication, and oxygen poisoning...

, arterial gas embolism and CO₂ retention

CO2 retention

CO2 retention is a pathophysiological process in which too little carbon dioxide is removed from the blood by the lungs. The end result is hypercapnia, an elevated level of carbon dioxide dissolved in the bloodstream. Various diseases may lead to this state; disturbed gas exchange may lead to...

. Dysbaric osteonecrosis

Dysbaric osteonecrosis

Dysbaric osteonecrosis or DON is a form of avascular necrosis where there is death of a portion of the bone that is thought to be caused by nitrogen embolism in divers...

 is an example of the effects on the bones and joints of bubbles from decreased pressure in a nitrogen saturated diver.

Marine hazards

Dangers in the ocean that can affect divers include marine life, marine infections, polluted water, ocean currents, waves and surges and man-made hazards such as boats, fishing lines and underwater construction. Diving medical personnel need to be able to recognize and treat accidents from large and small predators and poisonous creatures, appropriately diagnose and treat marine infections and illnesses from pollution as well as diverse maladies such as sea sickness, traveler's diarrhea

Traveler's diarrhea

Traveler's diarrhea , is the most common illness affecting travelers. An estimated 10 million people—20% to 50% of international travelers—develop it annually. TD is defined as three or more unformed stools in 24 hours passed by a traveler, commonly accompanied by abdominal cramps, nausea, and...

 and malaria

Malaria

Malaria is a mosquito-borne infectious disease of humans and other animals caused by eukaryotic protists of the genus Plasmodium. The disease results from the multiplication of Plasmodium parasites within red blood cells, causing symptoms that typically include fever and headache, in severe cases...

.

Fitness to dive

All divers should be free of conditions and illnesses that would negatively impact their safety and well-being underwater. The diving medical physician should be able to identify, treat and advise divers about illnesses and conditions that would cause them to be at increased risk for a diving accident.

Some reasons why a person should not be allowed to dive are as follows:

Disorders that lead to altered consciousness: conditions that produce reduced awareness or sedation from medication, drugs, marijuana

Cannabis (drug)

Cannabis, also known as marijuana among many other names, refers to any number of preparations of the Cannabis plant intended for use as a psychoactive drug or for medicinal purposes. The English term marijuana comes from the Mexican Spanish word marihuana...

 or alcohol

Alcoholic beverage

An alcoholic beverage is a drink containing ethanol, commonly known as alcohol. Alcoholic beverages are divided into three general classes: beers, wines, and spirits. They are legally consumed in most countries, and over 100 countries have laws regulating their production, sale, and consumption...

; fainting, heart problems and seizure

Seizure

An epileptic seizure, occasionally referred to as a fit, is defined as a transient symptom of "abnormal excessive or synchronous neuronal activity in the brain". The outward effect can be as dramatic as a wild thrashing movement or as mild as a brief loss of awareness...

 activity.

Disorders that inhibit the "natural evolution of Boyle's Law

Boyle's law

Boyle's law is one of many gas laws and a special case of the ideal gas law. Boyle's law describes the inversely proportional relationship between the absolute pressure and volume of a gas, if the temperature is kept constant within a closed system...

": conditions or diseases that are associated with air trapping

Air trapping

Air trapping, also called gas trapping, is an abnormal retention of air in the lungs where it is difficult to exhale completely. It is observed in obstructive lung diseases such as asthma, bronchiolitis obliterans syndrome and chronic obstructive pulmonary diseases such as emphysema and...

 in closed spaces, such as sinuses, middle ear, lungs and gastrointestinal tract. Severe asthma

Asthma

Asthma is the common chronic inflammatory disease of the airways characterized by variable and recurring symptoms, reversible airflow obstruction, and bronchospasm. Symptoms include wheezing, coughing, chest tightness, and shortness of breath...

 is an example.

Disorders that may lead to erratic and irresponsible behavior: included here would be immaturity, psychiatric disorders, diving while under the influence of medications, drugs and alcohol or any medical disorder that results in cognitive defects.

Hyperbaric Medicine

Recompression treatment in a hyperbaric chamber was initially used as a life-saving tool to treat the "bends" in caisson workers and divers who stayed too long at depth and developed decompression sickness. Now, it is a highly specialized treatment modality that has been found to be effective in the treatment of many conditions where the administration of oxygen under pressure has been found to be beneficial. Studies have shown it to be quite effective in some 13 indications

Undersea and Hyperbaric Medical Society

The Undersea and Hyperbaric Medical Society is the primary source of information for diving and hyperbaric medicine physiology worldwide.-History:The Undersea Medical Society grew from the close associations of a small group of scientists...

approved by the Undersea and Hyperbaric Medical Society. Some success has been also seen in numerous other conditions that are being treated in an "off-label" manner - but without backup from good evidence based studies.

External links

• Scubadoc's Diving Medicine Online
• Diving Diseases Research Centre (DDRC)
• Rubicon Research Repository Diving Medical Literature
• SCUBA Diving and Asthma
• infos scuba diving restrictions - free download of complete text