Around 7% of SCUBA divers have asthma. This is a condition that affects the airways. When you have asthma your airways are almost always sensitive and inflamed. If something irritates your airways they become narrower, making it harder to breathe. Their lining becomes inflamed and often phlegm is produced. Coughing is the most common asthma symptom, along with shortness of breath and wheezing.
Numerous concerns exist regarding people with asthma who go SCUBA diving. These include pulmonary barotrauma (pressure damage to the lungs), pneumothorax (collapsed lung), bubbles in the blood and ear barotrauma resulting in pains in the ear. Despite these concerns, a paucity of information exists linking asthma to increased risk of diving complications.
Advice and regulations on SCUBA diving with asthma vary between countries. The British Sub-Aqua Club, for example, suggests that people with mild asthma may dive provided that: they do not have asthma that is triggered by cold, exercise, stress or emotion; the asthma is well controlled; and they have not needed to use an inhaler, or have had any symptoms, in the previous 48 hours.
A recently published article in the Clin Rev Allergy Immunol journal examines the currently available literature to allow for a more informed decision regarding the possible risks associated with diving and asthma. It examines the underlying physiological principles associated with diving, including Henry’s law and Boyle’s law, to provide a more intimate understanding on physiological changes occurring in the respiratory system under compressive stress. It concludes that under the right circumstances, the patient with asthma can safely participate in recreational diving without apparent increased risk of an asthma-related event.
Journal reference: Clin Rev Allergy Immunol, October 1, 2005; 29(2): 131-8.