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.


Heart surgeries are often associated with a risk for blood pressure spikes. One reason for this might be that many people having these surgeries already have high blood pressure. If your blood pressure is poorly controlled before going into surgery, there is a good chance you’ll experience complications during or after surgery.

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

According to the National Heart, Lung, and Blood Institute, these are the ranges for normal, borderline, and high blood pressure:

  • Normal: less than 120 over less than 80
  • Borderline: 120 to 139 over 80 to 89
  • High: 140 or higher over 90 or higher

Having poorly controlled high blood pressure means that your numbers are in the high range and you’re not 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 going off of them suddenly. 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. Often some medications can even be taken on the morning of surgery, so you don’t have to miss a dose. It is 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 and your blood pressure goes back down after the pain has been treated.


Anesthetics, the drugs used to put you to sleep during surgical procedures, can have an effect on your blood pressure. Changes can happen while you’re being put to sleep and then when you’re coming off of the drugs. During the early stages of being put to sleep, anesthesia can cause a spike in blood pressure from around 20 to 30 mmHg, and possibly higher for people with poorly controlled high blood pressure. Recovery from anesthesia can hit people with high blood pressure harder as well.

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 is needed. This is caused by less oxygen being in your blood, a condition called hypoxemia. Your blood pressure can increase as a result.

Pain Medications

Certain drugs, prescription or over the counter (OTC), can increase your blood pressure. If you already have high blood pressure before surgery, talk to your doctor about pain management options. He may recommend different medications or have you alternate drugs, so you’re not taking one over the long term.

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


If you don’t have a history of high blood pressure, the spike in your blood pressure after surgery will most likely be temporary, typically lasting anywhere from one hour 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 before surgery. For example, you may be able to take your blood pressure medication on the morning of surgery.