Scuba Diving With Asthma, Can You Be Cleared?

Asthma is the single most common reason a diver ends up needing a physician signature, and the most common reason they assume the answer will be no. It usually is not. Mild, well-controlled asthma is frequently compatible with recreational diving. What follows is what the published diving medical guidance actually says, which histories clear, which need an in-person evaluation, and what to have ready.

Why asthma gets a closer look underwater

The concern is air trapping. Anything that impedes airflow out of the lungs puts a diver at risk of pulmonary overinflation as they ascend and the gas in their chest expands, which can rupture alveoli and send gas into the arterial circulation. The official guidance to physicians lists asthma alongside COPD and cystic lung disease as conditions that may cause that air trapping. This is why the questionnaire asks, and why the physician wants evidence rather than reassurance.

What the diving medical guidance actually says

The Diver Medical Screen Committee publishes guidance to the physician alongside the form itself. On asthma it is specific, and it is worth reading before you assume the worst or the best.

Guidelines from the Undersea and Hyperbaric Medical Society and the British Thoracic Society recommend that asthmatics be advised not to dive if they have wheeze brought on by exercise, cold or emotion. Asthmatic individuals who are currently well controlled and have normal pulmonary function tests may dive. Those with a history of severe or unpredictable attacks are not fit to dive.

Two details surprise people. First, a mildly obstructed spirometry tracing on its own is not treated as a bar to diving, provided there is no deterioration after exercise. Second, the guidance considers an exercise test the best way to assess fitness, and specifically says inhalation challenge tests are not standardized enough to interpret for scuba. So the useful evidence is how you perform, not whether a single number sits slightly below predicted.

The asthma histories that usually clear

On DiveSlip, mild, well-controlled asthma with recent normal spirometry sits on the published list of histories that frequently clear with records plus a live video visit. In practice the profile that clears looks like this: your asthma is stable, your triggers do not include exercise or cold air, you have not had a severe attack or hospital visit, your medication is routine and your recent lung function is normal.

Carrying a rescue inhaler is not a disqualifier. The guidance expects divers cleared with a breathing history to carry their regular inhalers and to stay out of the water when symptoms suggest a flare.

The asthma histories that need an in-person evaluation

An honest evaluation has to know its limits, and some asthma histories genuinely exceed what a records review and a video visit can settle. Wheeze triggered by exercise or cold air is the clearest example, because that is the exact mechanism that matters at depth and because the guidance calls for an exercise test to resolve it. A history of severe or unpredictable attacks is another.

Two related histories stop the online path outright at DiveSlip, before you pay: a previous collapsed lung (pneumothorax), and lung surgery in the past 12 months. Both change the risk picture in ways video cannot assess. If something like that surfaces in an evaluation you already paid for, the referral comes with an automatic 100% refund. DAN maintains a referral network at dan.org for finding a dive medicine physician in person.

The records worth having ready

If you flagged asthma, recent spirometry is the record that does the most work, because it is the objective evidence behind every claim about control. A current medication list is the second. Clinic notes from your last asthma review help if your history has changed recently. Clear phone photos are fine.

If your last spirometry is years old or you have never had one, say that at intake instead of booking and hoping. The physician reviews what you send before the visit, so the honest version gets you a straight answer about what to obtain first rather than a wasted appointment.

How the evaluation works

You flag your yes answers on the Diver Medical Participant Questionnaire, upload the records they relate to, and meet Dr. Adam Z. Kawalek, a board-certified internist and PADI certified diver, on a scheduled video visit of about 15 minutes. When clearance is appropriate, the completed RSTC Physician’s Evaluation Form is in your inbox the same day, signed under his own name, NPI and state license. It is $91 flat, and if you cannot be safely cleared online you get the referral and every dollar back.

For the process end to end, see our guide to scuba medical clearance online. If your own doctor has already declined to sign the form, that is common and rarely about your health; here is why it happens and what to do.