The RSTC medical questionnaire is the same form used globally by PADI, SSI, RAID, and almost every other agency. It has roughly a dozen yes/no questions covering heart, lung, ear, neurological, and metabolic conditions. A yes answer does not disqualify you — it triggers a referral to a dive doctor, who clears or declines you based on a proper exam. Most yes-answers result in clearance with paperwork. Lying on the form is a bad idea both medically and legally. Do this before you book, not at the shop on day one.
What RSTC actually is
The World Recreational Scuba Training Council is the umbrella body that sets minimum standards for recreational diving instruction. PADI, SSI, RAID, NAUI, SDI, and most other agencies are members. One of the things RSTC standardises is the Diver Medical Participant Questionnaire — the form you fill in before any Open Water course or fun dive at a new shop.
The form was last revised in 2020 by a panel that included the Divers Alert Network (DAN), Duke University’s Hyperbaric Center, and the Undersea and Hyperbaric Medical Society. The 2020 version is shorter and less paranoid than the older 2007 version. Fewer questions are automatic disqualifiers. More are routed to “see a dive-trained doctor.”
The form has two parts:
- A short screen of ten questions. If you tick “no” to all of them, you sign and you’re done.
- A longer second-page list broken into category headings. You only reach this if you ticked yes to something on the screen. Each category has more granular questions that the dive doctor will use to evaluate fitness.
Why the form exists
Diving is medically distinct from almost any other recreational activity because of three things:
- Pressure changes compress and expand gas in your body’s air spaces (ears, sinuses, lungs, sometimes teeth and the gut).
- Breathing dense gas at depth changes how your lungs and heart work.
- Inert gas loading — nitrogen dissolves into your tissues during the dive and must come out slowly on ascent. If it comes out as bubbles, you get decompression sickness.
Any condition that interferes with airway management, gas exchange, circulation, or consciousness becomes a much bigger problem 18 metres underwater than it does on land. The form is the first filter.
The categories on the form, explained
Below is every question category on the current RSTC questionnaire, what it’s asking about, why diving makes it relevant, and what typically happens if you tick yes. Typically is doing a lot of work in that sentence — your specific outcome depends on your specific condition and a real evaluation by a dive-trained physician.
Heart and circulation
The form asks about heart attack, heart surgery, stents, blood pressure medication, arrhythmias, and a few related items.
Why it matters underwater. Diving is moderate aerobic exercise in a cold, dense environment. Cold water plus exertion plus immersion (which shifts blood into your chest) puts genuine load on the heart. A heart that’s fine for office life may not be fine at 20 metres in a current. Immersion pulmonary edema is the specific concern — fluid in the lungs triggered by the cardiovascular shift of being submerged.
Typical outcome if you tick yes. Cardiology workup with a dive-trained physician, often including a stress test. Well-controlled hypertension on a single drug is frequently cleared. A heart attack within the last six to twelve months is usually a no. Stents are case-by-case.
Lungs and respiratory
Asthma, collapsed lung (pneumothorax) history, chronic bronchitis, COPD, cystic fibrosis, recurrent chest infections.
Why it matters. Your lungs are the largest air space in your body. On ascent, gas inside them expands. If anything obstructs that expansion — bronchospasm, scar tissue, a bleb — you risk pulmonary barotrauma and arterial gas embolism, which is fatal in minutes.
Typical outcome. A spontaneous pneumothorax (without trauma) is one of the few near-absolute contraindications because of recurrence risk. Asthma is much more nuanced now than it was twenty years ago and depends on type, trigger, and control — see the diving with asthma guide for the detail. Anything chronic gets a pulmonologist letter.
Recent surgery or injury
Surgery in the last twelve months, head injury with loss of consciousness, back or spine surgery, ostomy.
Why it matters. Healing tissue can have trapped gas pockets or weakened structures. Diving stresses healing. The specific worry varies — chest surgery means lung concerns, spine surgery means neurological assessment, abdominal surgery means gas-trapping risk in the gut.
Typical outcome. Wait until your surgeon and a dive doctor agree you’re healed. For most uncomplicated surgeries, three to six months is the floor. Major chest or neurological surgery is much longer.
Ears, sinuses, and equalisation
History of ear surgery, hearing loss, vertigo, recurrent ear infections, sinus surgery, deviated septum.
Why it matters. Your middle ears and sinuses must equalise pressure on descent and ascent. If they can’t, you get barotrauma — pain, fluid behind the eardrum, sometimes a ruptured drum and water rushing into the middle ear, which causes severe vertigo underwater.
Typical outcome. Most of these are clearable with an ENT exam confirming the Eustachian tubes work. Tube grommets (ventilation tubes) currently in place are usually a no until they fall out and the eardrum heals. See the ear equalisation problems guide for the practical side.
Neurological
Epilepsy or seizures, history of stroke, brain or spinal cord surgery, persistent migraine with aura, multiple sclerosis.
Why it matters. A seizure underwater is fatal — your regulator falls out and you drown. Many neurological conditions also interact badly with nitrogen narcosis at depth or oxygen toxicity on technical dives. Stroke history raises clot risk that the cardiovascular load of diving can aggravate.
Typical outcome. Active epilepsy is one of the firm no-go answers because the seizure risk underwater is non-recoverable. Migraine with aura, controlled and rare, often gets cleared. Stroke history is heavily case-by-case based on cause and recovery.
Behavioural health and medications
Anxiety attacks, panic disorder, claustrophobia, depression with current medication, ADHD medication, history of addiction.
Why it matters. Diving requires calm problem-solving in a tight, dark, sometimes disorienting environment. Anxiety underwater turns small problems into emergencies. Many psychiatric medications also alter how you respond to nitrogen narcosis and increase seizure risk on enriched-air mixes.
Typical outcome. Stable, well-managed conditions on consistent medication regimens are routinely cleared. SSRIs are common among divers. The concern is acute crises, not the diagnosis itself. Active addiction or recent psychiatric hospitalisation is usually a no until things stabilise.
Diabetes
Type 1, type 2, insulin or oral medication use, history of hypoglycaemia.
Why it matters. A hypoglycaemic episode underwater is dangerous — confusion, loss of consciousness, drowning. The DAN diabetes and diving protocol changed in the mid-2000s. Many type 1 and type 2 diabetics dive safely now with structured pre-dive blood sugar checks and a dive plan that allows for hypoglycaemia management.
Typical outcome. Cleared if HbA1c is well-controlled, no severe hypos in the last twelve months, and the diver agrees to the DAN diabetes protocol (pre-dive glucose check, sugar source accessible to the buddy, conservative dive profile). Recent severe hypoglycaemia is typically a no.
Pregnancy
Currently pregnant or attempting to become pregnant.
Why it matters. Studies on diving and pregnancy are limited because nobody runs deliberate experiments on pregnant women. The theoretical concern is that nitrogen bubbles forming in the maternal circulation could affect the foetus, which can’t off-gas the way an adult can. Most agencies recommend against diving while pregnant out of caution.
Typical outcome. Standard guidance is to not dive while pregnant. Snorkelling is generally considered fine. After delivery, most physicians clear divers within weeks once recovered.
Gut and metabolic
Recent abdominal surgery, hernia, Crohn’s, ulcerative colitis, severe acid reflux.
Why it matters. Gas trapped in the gut expands on ascent. Severe reflux means the regulator triggers reflux episodes underwater. Active inflammatory bowel disease in flare can interact badly with diving stress.
Typical outcome. Most of these are clearable when stable and post-surgical. Hernias are usually fixed surgically first.
Other items the form also asks
Recent inability to do moderate exercise (climb two flights of stairs without resting), age above a threshold (50+ triggers extra screening with some agencies), use of recreational drugs, currently taking any prescription medication.
A quick reference table
Below is a rough map of common yes-answers and what typically happens next. This is general orientation only. Your actual outcome depends on a dive-trained physician examining your specific situation.
| Yes-answer | Typical next step | Typical outcome |
|---|---|---|
| Well-controlled high blood pressure on one medication | Doctor’s signature | Usually cleared |
| Asthma, last symptoms more than 12 months ago | Spirometry + dive doctor exam | Often cleared |
| Asthma, active symptoms or rescue inhaler use | Dive doctor + pulmonologist | Case-by-case, often not cleared |
| Past spontaneous pneumothorax | Pulmonologist + dive doctor | Usually not cleared |
| Stable depression on SSRI | Doctor’s signature | Usually cleared |
| Active panic disorder | Mental health and dive doctor | Often deferred until stable |
| Type 1 diabetes, HbA1c well-controlled | Dive doctor + DAN protocol agreement | Often cleared with structured plan |
| Type 1 diabetes with recent severe hypoglycaemia | Endocrinologist + dive doctor | Often not cleared until stable |
| Currently pregnant | None — wait | Defer until post-pregnancy |
| Heart attack 10+ years ago, no recurrence | Cardiology workup, often stress test | Often cleared |
| Heart attack within 6 months | Cardiology | Usually not cleared yet |
| Epilepsy with recent seizures | Neurology | Usually not cleared |
| Migraine with aura, occasional, well-controlled | Doctor’s signature | Often cleared |
| Recent abdominal surgery | Surgeon + dive doctor | Wait until healed, then usually cleared |
| Ear tubes currently in place | ENT | Usually not cleared until tubes are out and eardrum healed |
Common myths
“If I tick yes to anything I can’t dive.” False for most conditions. The form is a routing tool, not a verdict. The majority of yes-answers result in clearance after a doctor’s signature. The form exists so that the shop is not the entity making medical calls — that’s the doctor’s job.
“If I tick no even though I should tick yes, I save myself the hassle.” Bad idea. If something happens underwater that’s linked to the condition you concealed, your travel insurance will likely refuse the evacuation claim, your dive insurance (if you have it) will refuse the chamber claim, and the shop and instructor have a paper trail showing you lied. Worse: you’ve put yourself in genuine danger to save two hours and a doctor’s fee.
“My GP can sign it.” Sometimes — depends on the agency, the country, and how comfortable the GP is. The better answer is a dive-trained physician. They know what to look for. DAN runs a public referral list at daneurope.org and diversalertnetwork.org with searchable directories of physicians trained in diving medicine.
“The shop will sort it on the day.” Some will, many won’t. Smaller shops on remote islands often don’t have a dive doctor on hand. You’ll lose half a day or more travelling to find one. Plan ahead.
Where to find a dive-trained physician
The Divers Alert Network maintains the most useful global directories:
- DAN Europe (Europe, Middle East, Africa) — referral list at daneurope.org
- DAN World (Americas, Caribbean, Asia-Pacific) — referral list at diversalertnetwork.org
- DAN AP (Asia-Pacific specific) — danap.org
- UKDMC (UK Diving Medical Committee) — has its own list at ukdmc.org
In countries with a strong commercial diving industry (UK, Norway, Australia, Singapore), there are also occupational dive physicians who handle recreational referrals.
What a dive medical exam actually involves
Expect 30 to 60 minutes. The physician will:
- Review your filled-in questionnaire
- Take a focused medical history with follow-up on anything you ticked yes
- Listen to your heart and lungs
- Check your ears and nose, often with an otoscope and sometimes a pressure test on the eardrums
- Often run spirometry (a breath test for lung function)
- Sometimes order an ECG if there’s any cardiovascular concern
- Sign the agency form (PADI’s is RSTC-format, SSI and RAID use the same questions)
Cost in 2026, rough ranges.
- UK and Northern Europe: 80–200 GBP / 100–230 EUR
- Continental Europe: 60–150 EUR
- US: 100–300 USD, varies wildly by state and insurance
- Thailand (Bangkok or Phuket): 1,500–3,500 THB (40–100 USD)
- Australia: 150–300 AUD
The medical is valid for one to five years depending on the country and your age. Some operators want one within the last twelve months for older divers.
When to do this
Before you book the course. Not at the shop on day one. Two reasons.
First, if the doctor declines you, you’ve cancelled a course before paying the full deposit. Trying to get a refund on a non-refundable course because of a medical issue you ticked yes to in advance is a long argument.
Second, dive doctors are not on every street corner. Even in Bangkok, there are only a handful with dive medicine training. On Koh Tao, there’s effectively one. If you arrive on Monday for a Tuesday course start and the doctor is fully booked until Thursday, you’ve lost half your trip.
Best practice: fill in the form online or as a printout from PADI or SSI’s website, identify any yes-answers, find a dive doctor before your trip, get the signed clearance in hand. Then book.
What if I’m in good health and tick no to everything?
You sign the form, hand it in, and dive. That’s the design. The form is specifically optimised so the majority of healthy beginners can skip the medical exam entirely. The structure of the 2020 revision was driven by the fact that the older form was sending too many fit, healthy people to doctors unnecessarily — which was both wasteful and a barrier to people getting into the sport.
If you have a clean form and you’re under 45, you’re done.
Ready to book?
We compare dive shops on Koh Tao with transparent pricing, instructor language coverage, and class size — so once your medical clearance is in hand, you can pick the shop that fits.