Nothing on this page is medical advice. If you have any health condition, take any medication or are unsure about your fitness, talk to a doctor before you start a course, ideally one familiar with diving medicine.
Why diving asks so much of your body
Under water, changes in pressure act on every air space in your body. Your ears and sinuses must equalize. Your lungs have to work against denser gas. Cold water, carrying gear and swimming against a current all add strain on your heart. A condition that causes no trouble on land can matter a great deal underwater, where you can't simply stop and sit down.
The medical questionnaire
Before any in-water training, the school will ask you to complete a medical questionnaire. It asks about your history and current health, often covering areas such as:
- heart and blood pressure
- lungs and breathing, including asthma
- ears and sinuses
- seizures or loss of consciousness
- diabetes
- mental health
- pregnancy
- current medications and recent surgery
Some forms also ask about age and general fitness. The exact form and rules depend on the agency and sometimes on local law.
When an answer means seeing a doctor
If you answer yes to certain questions, the school can't let you dive until a doctor has reviewed the form and signed it to say you may dive. This isn't a judgment about you. It is a standard step that protects you and the people diving with you. Some regions or schools require a medical check for everyone.
Be honest on the form. Leaving something out doesn't make you safer underwater. It only removes the chance for a doctor to spot a risk or suggest a way to manage it.
Finding the right doctor
Your own doctor is a good start, since they know your history. Diving medicine is a specialty, though, and some conditions need a doctor with experience in it. Your dive school or your training agency may be able to point you toward one. Bring the questionnaire and any guidance that comes with it to the appointment.
Everyday things that affect a dive
Even healthy divers have days when they shouldn't dive. Courses teach you to sit out a dive if you have a cold, blocked sinuses or an ear problem, feel unwell or very tired, or have been drinking alcohol. If you take medication, ask a doctor whether it affects diving, including over-the-counter remedies.
General fitness
Diving isn't usually strenuous, but sometimes it has to be. You may need to swim against a current, carry heavy gear over rocks or help a buddy at the surface. Being comfortable swimming and reasonably fit gives you a margin for those moments. How fit you need to be, and how to get there safely, is another question for your doctor.
Fitness FAQ
Can I dive if I have asthma?
That depends on the individual case. Only a doctor, ideally one familiar with diving medicine, can assess it. Answer the questionnaire honestly and follow the doctor's advice.
Do I need a medical every year?
Rules differ between agencies, schools and countries, and between people with and without health conditions. Ask your school, and follow any advice from your doctor about review dates.