1. What are the risks?
The main risk is air trapping in the lungs when surfacing. Asthma can prevent the lungs emptying completely because of airway spasm. If this happens when surfacing then the lungs can expand and the small air spaces within the lungs can rupture. This causes pulmonary barotrauma, which allows air to leak into the blood and can be fatal.

2. Can asthmatics dive?
Yes, under the following conditions. Your asthma must be allergic rather than triggered by exercise, cold air or emotion. If you are unsure about this talk to your GP. Diving involves physical activity, cold air and occasionally stressful situations. It is therefore important that your asthma is not provoked by diving itself.

It is possible to test if your asthma is exercise induced by performing an exercise test, for example a step test or running. You should exercise until your heart rate rises to 80% of (210 minus your age in years). For example, a 16 year old should exercise until the heart rate rises to 80% of (210-16), i.e. 155 beats per minute. You should measure your peak flow rate before exercise, and again 3 and 10 minutes after stopping. If the peak flow drops by more than 15% then your asthma is affected by exercise. This type of test should be performed under medical supervision.

3. How can I reduce the risks?
If your medical has been passed you will be asked to record your peak flow rate during the diving season. You should know your best reading. If any reading during the diving season drops more than 10% from this, or if you become wheezy then you should not dive until the peak flow rises again and stays high for at least 48 hours.

You must be especially careful not to hold your breath when surfacing.

Make sure your diving partner and expedition organiser know about your asthma and the treatment you are taking.

3. Where can I get more information?
Contact your GP in the first instance, or ScotSAC head office (The Cockburn Centre, 40 Bogmoor Place, Glasgow, G51 4TQ. Tel/fax 0141 425 1021) who will be able to give you details of a local medical referee.