Clinically reviewed by Dr. Ponlawat Pitsuwan, Physician, Takecare Medical Clinic Phuket.
Last reviewed: September 2026
Most people with well-controlled high blood pressure can dive safely in Phuket. But well-controlled means consistently below 130/80 mmHg at rest, stable on medication for at least four weeks, and cleared by a physician before your first dive. If your dive shop hands you a PADI medical form and you answer yes to high blood pressure, you need a doctor’s signature before you get on that boat.
You have booked a liveaboard out of Chalong pier. Three days, multiple dives daily, Shark Point, Anemone Reef, maybe Richelieu Rock if conditions hold. You filled in the PADI medical statement at check-in, ticked yes to blood pressure medication, and now the dive coordinator is asking for a physician’s signature before you can kit up. Your trip starts tomorrow. This is not the moment to discover that your GP at home is twelve time zones away and not answering emails.
I see this situation regularly, and it almost always resolves quickly when handled the right way. The bigger problem is the diver who ticks no on that form, dives anyway, and never considers what happens if something goes wrong at depth in Andaman Sea conditions. High blood pressure raises real cardiovascular risks underwater, and Phuket’s most popular dive sites are not gentle pool environments. Here is what you need to know before you descend.
What the PADI Medical Form Means When You Have High Blood Pressure
The PADI medical statement, based on WRSTC standards, lists specific conditions that require physician sign-off before diving. High blood pressure is one of them. Ticking yes does not mean you cannot dive. It means a doctor must assess you first.
Most Phuket dive operators take this seriously. If they do not check, your dive insurance almost certainly will. Diving without documented medical clearance when you have a known cardiovascular condition can void a DAN policy or travel insurance claim if a cardiac event or decompression incident occurs. That gap is not mentioned on most diving information pages, but I see it cause real problems for patients after the fact.
The clearance process is straightforward. A physician reviews your current blood pressure, your medication, your cardiovascular history, and signs the form if you are fit to dive. No dramatic workup in most cases. The problem is finding someone who can do it quickly and in English on a Phuket holiday timeline.
Blood Pressure Numbers That Matter for Diving With High Blood Pressure in Phuket
Dive medicine guidelines do not set a single universal cutoff. The standard used by most dive physicians is a resting reading consistently below 140/90 mmHg on treatment, with many preferring readings consistently below 130/80 mmHg measured at home over several days.
A single reading on the morning of a dive is not enough on its own. White-coat effect, dehydration from the previous day, or a heavy night in Patong can all push numbers up temporarily. What matters is your pattern over time and what your medication is actually doing.
On the day itself, most experienced Phuket dive operators check your blood pressure before boarding. A systolic above 160 or a diastolic above 100 on the dock is typically a no-dive day regardless of your paperwork. I tell patients to treat the morning of a dive like the morning of something physically demanding. Hydrate the night before. Sleep. Skip the alcohol.
Your Blood Pressure Medication and What Dive Doctors Look At
Most antihypertensive medications are compatible with recreational diving, but the drug class matters.
Beta-blockers reduce your maximum heart rate. That is fine at rest, but at a site like Shark Point or the channel north of Koh Doc Mai, where you are finning hard against current, reduced exercise tolerance is a real factor. I do not automatically exclude divers on beta-blockers, but we talk through realistic exertion limits.
Diuretics increase urine output. In Phuket’s heat on a full-day boat dive, dehydration compounds fast, and dehydration is a known risk factor for decompression sickness. A diver on a diuretic who skips fluids on a five-hour boat trip and does three dives is taking a layered risk that most generic diving articles never mention.
ACE inhibitors can cause a dry cough in some people. Underwater, an unexpected coughing fit is alarming and occasionally dangerous. If you take an ACE inhibitor and this is a known side effect for you, it needs to be part of your assessment. Calcium channel blockers can cause lightheadedness on standing, which matters when you are hauling equipment on a rocking boat in Andaman Sea swell.
None of these are automatic disqualifiers. They are factors a physician weighs in the context of your actual situation.
When High Blood Pressure Becomes a Disqualifier for Diving
Controlled hypertension with no evidence that elevated pressure has already affected your heart, kidneys, or eyes is generally compatible with recreational diving. What matters in practice is whether your blood pressure has been poorly managed long enough to start causing problems elsewhere. If the answer is yes, diving is not appropriate regardless of your current readings.
Other genuine red flags: your medication was changed or started within the last four weeks, you have missed doses recently, you are experiencing chest tightness, breathlessness, or dizziness, or you had a reading above 180/110 in the past month. Any of these means we need to talk before you dive.
Immersion pulmonary oedema is also worth naming. It is a sudden build-up of fluid in the lungs triggered by cold water, exertion, and the cardiovascular changes that come with full immersion. Hypertension is one of the main risk factors. Symptoms underwater include breathlessness, cough, and chest tightness. If that happens at depth, you face an emergency ascent, and an unplanned ascent carries its own decompression risk. This scenario is rare in well-cleared divers, which is exactly why the pre-dive check matters.
Getting Same-Day Dive Medical Clearance in Phuket
This is where the practical answer sits. You are in Phuket. You need a physician’s signature on a PADI medical form, or a clearance letter your dive operator will accept. You do not have time to fly home and see your GP.
At Takecare Clinic Phuket in Patong, this is something we handle regularly. No appointment needed. Walk in with your PADI medical statement or explain what your dive operator has asked for. We measure your blood pressure, take a brief cardiovascular history, review your medications, and if you are fit to dive, we issue documentation in English the same day. Most visits take under an hour.
If your blood pressure is higher than expected on the day, we assess whether that is situational or a genuine trend, start a management plan if needed, and advise on realistic next steps for your trip. A high reading at a dive shop does not automatically end your holiday. It means you need a clinical assessment, not a guess.
Bring your medication packaging or a list of what you take, the dosage, and how long you have been on it. If you have recent blood pressure readings from home, bring those too. The more information you arrive with, the faster the assessment. We also issue medical certificates in Phuket for dive fitness and other purposes, all in English.
Phuket Dive Sites and the Cardiovascular Demands Most Articles Ignore
Generic articles treat all diving as equal. It is not. A relaxed shallow reef dive in calm water off Kata beach is a different cardiovascular event from a current dive at Shark Point, a liveaboard schedule with four dives daily, or a descent to the King Cruiser wreck at thirty metres.
Phuket’s best sites, including Richelieu Rock, Anemone Reef, and the Similans by liveaboard, regularly involve current, thermocline temperature drops, boat exertion, and the cumulative load of repeated dives over several days. For a diver with hypertension, each of those factors adds demand on the heart. I am not saying avoid them. I am saying know what you are signing up for and make sure your clinical picture supports it.
A diver who has been stable on the same medication for six months, whose readings sit consistently around 125/80, and who exercises regularly at home is in a very different position from someone newly started on treatment who has not checked their numbers since leaving home.
If your dive shop in Phuket has asked for a doctor’s signature, or if you want your blood pressure checked before your first dive, Takecare Clinic Phuket in Patong is open for walk-in visits with no appointment needed. We issue dive fitness assessments and medical documentation in English for tourists, expats, and residents across the island. Most visits are completed the same day. Come in before you kit up, not after something goes wrong.
What blood pressure reading is too high to dive?
Most dive physicians use 140/90 mmHg on treatment as the upper working limit, with many preferring a consistent home reading below 130/80. On the day of diving, a reading above 160/100 is typically a no-dive signal regardless of medication. A same-day check at Takecare Clinic Phuket can give you a documented assessment and clearance if your numbers are within range.
My dive shop in Phuket is asking for a doctor’s signature on my PADI medical form. Where can I get this quickly?
Takecare Clinic Phuket in Patong handles this with no appointment needed. Walk in with your form and your medication list, and we assess your blood pressure, cardiovascular history, and fitness to dive. If you are cleared, we issue the documentation in English the same day, which is considerably faster than trying to reach your home GP across time zones.
Can I dive in Phuket if I take blood pressure tablets?
In most cases, yes, but the specific drug class matters. Beta-blockers, diuretics, ACE inhibitors, and calcium channel blockers each carry different considerations for diving in Phuket’s tropical heat and current conditions. The answer depends on which medication you take, how long you have been stable on it, and whether any side effects have been reviewed by a physician who understands diving medicine.
I found out my blood pressure was high for the first time at the dive shop. Does this end my trip?
Not necessarily. A single high reading at a dive shop can reflect dehydration, heat, anxiety, or the previous night’s alcohol rather than a genuine blood pressure problem. Come to Takecare Clinic Phuket for a proper assessment. If the reading is situational, we can clear you the same day. If it reflects a real trend, we can start a plan and advise on whether diving remains realistic for this trip.
What happens if I have a hypertensive episode while diving at Shark Point or on a liveaboard?
The most serious risk is immersion pulmonary oedema, where fluid builds suddenly in the lungs, causing breathlessness, coughing, and chest tightness underwater. This may force an emergency ascent, which itself carries decompression risk. Bangkok Hospital Phuket operates a hyperbaric chamber for decompression emergencies. This scenario is rare in well-controlled, properly cleared divers, which is exactly why the pre-dive medical check matters.
Does diving without medical clearance affect my insurance if something goes wrong?
Yes, and this is the part most divers do not read until it is too late. If you have a known cardiovascular condition, did not disclose it, and did not obtain physician clearance before diving, both DAN dive insurance and most travel policies can deny a claim. Getting a clearance letter from a Phuket clinic before you board is not bureaucratic box-ticking. It is what keeps your coverage intact.
About the author: Dr. Ponlawat Pitsuwan is a physician at Takecare Clinic Phuket, a walk-in medical clinic based in Patong with English-speaking physician care and no appointment needed. He regularly assesses tourists, expats, and residents for dive fitness, including medical certificate sign-off for PADI and other agency forms, cardiovascular review for hypertensive divers, and same-day clearance documentation in English. His focus is straightforward, evidence-based care delivered in plain language.
