Scuba Diving with Asthma

Scuba diving is a super popular recreational activity, abroad as well as in South East Asia where some of the most spectacular dive sites are located.  With hundreds of thousands of people becoming newly certified every year, there are also a proportion of divers who are asthmatics. In the recent past, however, people with asthma were told not to scuba dive due to the mostly theoretical dangers that are present.

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The topic of asthma and diving has long been a controversial subject in the recreational diving community. Traditionally, divers with asthma have been excluded from diving. Asthma is a disease characterized by narrowing of the breathing tubes (bronchi) in response to a variety of stimuli. It is not a fixed response, and a patient can have a sudden worsening in lung function, called an “attack.” An asthma attack can be triggered by pollen and other so-called “allergens,” cold air, irritants in the atmosphere, colds or flu.

What do dive physicians think about diving with asthma? This subject has generated much discussion worldwide, and many physicians hold opposing viewpoints. Perhaps the most liberal guidelines are from the United Kingdom, which states that well-controlled asthmatics may dive – within two guidelines:

• Provided they have not needed a bronchodilator within 48 hours;
• and if they do not have cold-, exercise- or emotion-induced asthma.In Australia, the most conservative country in this respect, all divers are expected to pass a spirometry (lung function) test, to exclude asthma, prior to certification.

Aspiring scuba divers need a doctor’s medical clearance before becoming certified to scuba dive. Many doctors, have been reluctant to allow asthmatics to scuba dive, mostly based on theoretical concerns. However, studies on scuba diving accidents have not shown that asthmatics are at an increased risk for injuries. This may be because people with significant asthma may choose not to scuba dive because the activity causes an increase in asthma symptoms.

Guidelines for Scuba Diving If You Have Asthma

Despite data not showing that asthmatics are at a significant increased risk for diving injuries, many diving medicine authorities still recommend that asthmatics follow special guidelines:

• People with past or present asthma should see a doctor familiar with the risks of asthma in scuba diving for a complete physical examination andspirometry.
• Scuba divers should have normal spirometry at rest, and in response to an exercise challenge which can be performed in a doctor’s office. Those with abnormal spirometry at rest, in response to exercise, or those who experience asthma symptoms with cold/dry air exposure should not dive.
• Asthma should be controlled with medications before a person participates in scuba diving.
• A person should not scuba dive if he is experiencing an increase inasthma symptoms, or if he has needed to use a rescue inhaler in the past few days prior to a planned dive.

It would therefore seem reasonable for a well-controlled asthmatic, with normal spirometry and without the need for frequent rescue inhaler use, to participate in scuba diving. It is important for asthmatics to be aware of the possible increased risk for injuries during scuba diving, which could potentially be life-threatening, and to discuss these risks with their doctor.

Asthmatic scuba divers should have frequent, routine doctor visits with spirometry performed to ensure that their asthma is well-controlled prior to diving. It would also seem reasonable for an asthmatic to use a rescue inhaler approximately 30 minutes before diving as a preventative measure against asthma symptoms, just as many asthmatics do before other forms of exercise.