Those who attempt to conceal their asthma do so in reckless disregard not only for their own lives, but also for those who might be called upon to rescue them. Most diving medical experts agree that if a person has had no symptoms or signs whatsoever of asthma for at least five years and has required absolutely no anti-asthma medication for this period, and has a normal diving medical examination including breathing tests, then they should be allowed to dive, after explanation of the risks. This test, which can be performed in most specialist lung function laboratories, involves breathing a salt water mist from an ultrasonic nebuliser, with breathing tests to determine whether bronchial narrowing results. If it does, then the person is still susceptible to an acute asthma attack while underwater, and should not dive. A negative test provides additional reassurance that the person is unlikely to develop asthma while diving.
Snorkel diving is much less risky for people with asthma than scuba diving.
The main reason for the difference is that snorkellers do not take air in while at depth, and thus there is much less risk of bursting the lung during ascent. Common sense dictates, however, that one's asthma should be stable and controlled before snorkelling as accidental aspiration of water and exercise associated with swimming against a current can also lead to an asthma attack. Some of the best underwater videos and films have been made by divers using a snorkel, goggles and a hand-held camera. Further information For more information about asthma and diving, talk to your doctor, your pharmacist, or local Asthma Foundation. Please consult your family doctor or specialist respiratory physician if you have further questions relating to the information provided here.