Before surgery · Heart & circulation
High Blood Pressure Before Surgery
High blood pressure is one of the most common things people bring to surgery, and it's rarely a problem when it's controlled. The key is knowing which tablets to take, which your team may pause, and when a reading is high enough to wait.
The short answer
Why blood pressure matters for surgery
Anesthesia naturally makes your blood pressure swing up and down, and your medicines change how your body responds to those swings. Well-controlled pressure gives the smoothest, safest anesthetic. Pressure that's very high and untreated raises the risk of heart strain, bleeding and stroke around the time of surgery — which is why teams want it reasonably controlled first.
Your blood pressure medicines
- Usually continue: beta-blockers (e.g. bisoprolol, atenolol) and calcium-channel blockers (e.g. amlodipine) — stopping beta-blockers suddenly can be risky, so keep taking them unless told otherwise.
- Often held on the day: ACE inhibitors ("-pril", e.g. ramipril, lisinopril) and ARBs ("-sartan", e.g. losartan, candesartan), because of the bigger blood-pressure drop under anesthesia.
- Sometimes adjusted: diuretics (water tablets) are occasionally paused on the morning. Follow your team's specific advice.
Not sure which of yours is which? The take-or-hold medication checker gives you a plain answer for each one — but your team's instruction always wins.
On the day
Take the tablets you've been told to continue with a small sip of water, even if you're fasting — that sip is allowed for essential medicines. Bring your list, and don't be alarmed if your reading is up when you arrive; nerves commonly nudge it higher, and the team takes that into account.
In the weeks before
Frequently asked questions
Should I take my blood pressure tablets on the morning of surgery?
Take most of them as normal with a small sip of water — but there's an important exception. ACE inhibitors (names ending in '-pril') and ARBs ('-sartan') are often held on the morning of surgery because they can cause a big drop in blood pressure under anesthesia. Always confirm each of your tablets with your pre-op team.
Why are ACE inhibitors and ARBs treated differently?
They blunt your body's ability to keep blood pressure up during anesthesia, which can lead to a pronounced drop. Many teams ask you to skip the dose on the day of surgery (and sometimes the evening before). Beta-blockers and calcium-channel blockers, by contrast, are usually continued.
Can surgery be cancelled because my blood pressure is too high?
It can, if your blood pressure is very high and uncontrolled, because that raises the risk of heart and stroke complications during surgery. Mildly raised readings — including nerves-on-the-day 'white coat' spikes — usually don't stop a procedure. Keeping your BP well controlled in the weeks before helps.
What should I bring?
Bring an up-to-date list of all your blood pressure medicines and doses, or the boxes themselves. If you monitor at home, a recent set of readings is useful too. It helps your team continue the right treatment smoothly.