Overview

All surgeries have the potential for certain risks, even if they’re routine procedures. One of these risks is the alteration of blood pressure.

People can experience high blood pressure after surgery for a number of reasons. Whether or not you develop this complication depends on the type of surgery you’re having, the type of anesthesia and medications administered, and whether or not you had issues with blood pressure before.

Understanding blood pressure

Blood pressure is measured by recording two numbers. The top number is systolic pressure. It describes the pressure when your heart is beating and pumping blood. The bottom number is diastolic pressure. This number describes the pressure when your heart is resting between beats. You’ll see the numbers displayed as 120/80 mmHg (millimeters of mercury), for example.

According to the American College of Cardiology (ACC) and the American Heart Association (AHA), these are the ranges for normal, elevated, and high blood pressure:

  • Normal: less than 120 systolic and less than 80 diastolic
  • Elevated: 120 to 129 systolic and under 80 diastolic
  • High: 130 or higher systolic or diastolic 80 or over

History of high blood pressure

Heart surgeries and other surgeries involving major blood vessels are often associated with a risk for blood pressure spikes during surgery. It’s also common for many people undergoing these types of procedures to already have high blood pressure. If your blood pressure is poorly controlled before going into surgery, there’s a good chance you’ll experience complications during or after surgery.

Having poorly controlled high blood pressure means that your numbers are in the high range and your blood pressure isn’t being effectively treated. This could be because doctors haven’t diagnosed you before surgery, your current treatment plan isn’t working, or maybe you haven’t been taking medication regularly.

Medication withdrawal

If your body was used to blood pressure-lowering medications, it’s possible that you may experience withdrawal from suddenly going off of them. With certain medications, this means you could have a sudden spike in blood pressure.

It’s important to tell your surgical team, if they’re not already aware, what blood pressure medications you’re taking and any doses you’ve missed. Often some medications can even be taken on the morning of surgery, so you don’t have to miss a dose. It’s best to confirm this with your surgeon or anesthesiologist.

Pain level

Being sick or in pain can cause your blood pressure to be higher than normal. This is usually temporary. Your blood pressure will go back down after the pain has been treated.

Anesthesia

Undergoing anesthesia can have an effect on your blood pressure. Experts note that the upper airways of some people are sensitive to the placement of a breathing tube. This can activate the heart rate and temporarily increase blood pressure.

Recovery from anesthesia can hit people with high blood pressure harder as well. Factors such as body temperature and the amount of intravenous (IV) fluids needed during anesthesia and surgery can elevate blood pressure.

Oxygen levels

One possible side effect of surgery and being under anesthesia is that parts of your body might not receive as much oxygen as needed. This results in less oxygen being in your blood, a condition called hypoxemia. Your blood pressure can increase as a result.

Pain medications

Certain prescription or over-the-counter (OTC) drugs can increase your blood pressure. One known side effect of nonsteroidal anti-inflammatory drugs (NSAIDs) can be a small increase in blood pressure in people who already have high blood pressure. If you already have high blood pressure before surgery, talk to your doctor about pain management options. They may recommend different medications or have you alternate drugs, so you’re not taking one over the long term.

Here are some examples of common NSAIDs, both prescription and OTC, that can increase blood pressure:

What’s the outlook?

If you don’t have a history of high blood pressure, any spike in your blood pressure after surgery will most likely be temporary. It typically lasts anywhere from 1 to 48 hours. Doctors and nurses will monitor you and use medications to bring it back down to normal levels.

Having existing high blood pressure under control in advance will help. The best way to manage your risk for developing high blood pressure after surgery is to discuss a plan with your doctor.