I have asthma and i want to go scuba diving. Ive always wanted to go scuba diving but I know that having asthma might create some problems. How does the respiratory system work with scuba diving?

Usually people who are asthmatic are automatically deferred from scuba diving. It depends on your type of asthma. If you have allergy induced asthma there is a possibility of being cleared but if you have exercise induced asthma then you are really excluded from it. I recommend looking at your history of attacks and getting your doctor to conduct a spirometry test, as well as a total physical to check out your overall health.

Now, to explain WHY diving and asthma don’t go together, it isn’t a matter of not being able to breathe, it’s a matter of physics pertaining to changes in pressure and how it affects fluids.

When you go diving, the pressure on your body increases proportionately with your depth. This means that you breathe in more molecules of air and you have a higher density of air in your lungs. If you suffer an asthma attack underwater, first of all it is difficult for you to breathe which usually causes a tendency to panic, but also it makes it difficult and dangerous to bring you up to the surface. If you have even a partial blockage in your lungs it prevents air from escaping as it expands (because ascending causes all fluids to expand proportionately with the pressure decrease) which makes your lungs expand as well. If you cross the expansion threshold of your lungs it will cause a lung over expansion injury which causes a series of injuries: pneumothorax, subcutaneous emphysema, cardiopulmonary emphysema or an arterial gas embolism. Each of these is caused by expanding air being pushed into different parts of the body and all are potentially fatal.

I am sorry to burst your bubble (no pun intended considering the content) but with the risk of such serious injuries it is understandable why most people with asthma are precluded from diving. If you still really want to try it out I suggest discussing it with your doctor and trying it out in a pool first.