Some scuba divers go diving with asthma, sneaking the fact through their dive medical exam. Others have dived with asthma and have died from barotrauma or a burst lung.
What is Asthma?
Asthma occurs when the small airways in the lungs become blocked, due to inflammation or a build-up of mucous. This leads to difficulty breathing, wheezing, pains in the chest and shortness of breath.
An asthma attack can be caused by environmental changes, such as breathing cool, dry air, or pollens in the air; and can also be triggered by stress and anxiety.
The Australian Lung Foundation states that about 1 in 10 adults in Australia have asthma. And 1 in 5 children.
Asthma is usually controlled by the use of medications delivered in a “puffer.”
Risk Of Asthma When Scuba Diving
The risk for a scuba diver is when an asthma attack occurs underwater. The small airways can close up, trapping air in the lungs; and a diver can’t get relief by using their asthma puffer underwater.
The trapped air expands when the diver ascends, and if the air can’t get out of the lungs due to the inflammation or mucous build-up from the asthma attack, then the only way to relieve this pressure is to burst the lung.
This leads to other problems, that don’t need to be covered here, except to say that a scuba diver with a burst lung is in the “scuba death zone.”
Asthma Attacks Triggered By Scuba Diving
The following are a few ways in which asthma may be triggered by scuba diving.
- Dry air
The compressed air in a scuba tank has been dried when the tank is filled.
- Cool air
When air moves from the higher pressure in the tank to the lower pressure at the regulator, the air cools.
- Stress and anxiety
Most people are under some stress when scuba diving. That is, there is more stress underwater than when talking about the dive when safely on dry land.
- Environmental
Accidentally breathing salt or fresh water particles can also trigger an asthma attack
Can An Asthmatic Scuba Dive?
There is no clear agreement of opinion on whether an asthmatic should dive or not. Obviously, if the diver is showing symptoms of asthma they shouldn’t dive; the risk is too great.
The risk is when a diver with history of asthma, but doesn’t exhibit symptoms when entering the water, has an asthma attack underwater.
General opinion seems to be that an asthmatic can dive if the following are met:
- no symptoms of asthma in the past five years
- no use of anti-asthma medication in the past five years
- successful completion of a diving medical, including breathing tests
- the diver is aware of the risks when diving with asthma.
Can An Asthmatic Dive Only At Shallow Depths?
An asthmatic should not take the approach, “I’ll just stay in shallow water.” This is not a solution, as the majority of pressure change occurs in the first ten metres. That is, the pressure change between the surface and ten metres deep is 100%; while the pressure change between 20 meters and 10 metres is only 50%.
It is this pressure change that can burst a lung if the asthma attack prevents the air in the lungs from being released on ascent.
Disclaimer
The information in this article is intended as a guide only. It is not an authoritative statement. Scuba divers with asthma should consult their medical specialist for specific medical advice. The author has no liability for the use or misuse of the information contained in this article.
