High blood pressure after surgery, or postoperative hypertension, is common. It has a variety of causes, including anesthesia, inflammation, and pain.

High blood pressure after surgery is typically short term and resolves as the person heals. However, numerous medications can lower a person’s blood pressure, and lifestyle modifications can help blood pressure stay within a safe range.

This article explains high blood pressure, examines some reasons for postoperative hypertension, and highlights how a person can manage it.

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High blood pressure, or hypertension, is a medical condition where the pressure in a person’s arteries is persistently high.

Blood pressure readings give the following two measurements:

  • Systolic pressure: Systolic pressure is the first, top number. It measures the pressure in the arteries when the heart beats.
  • Diastolic pressure: Diastolic pressure is the second, bottom number. It measures the pressure in the arteries when the heart rests between beats.

So if a person’s systolic pressure is 120 millimeters of mercury (mm Hg) and their diastolic pressure is 80 mm Hg, a healthcare professional may say their blood pressure is “120 over 80” or write “120/80 mm Hg.”

The American Heart Association states that typical blood pressure is less than 120/80 mm Hg. It also gives the following information:

  • Blood pressure is high when it is 120–129 mm Hg over less than 80 mm Hg.
  • Stage 1 hypertension is when the systolic number is 130–139 mm Hg, or the diastolic number is 80–89 mm Hg.
  • Stage 2 hypertension is when the systolic number is 140 or higher, or the diastolic number is 90 or higher.

People can discuss their personal blood pressure goals with a healthcare professional.

Various factors can cause postoperative hypertension, including:

Preexisting hypertension

People with preexisting hypertension or cardiovascular conditions are likely to experience fluctuations in blood pressure after surgery.

Anesthesia

During anesthesia, some medications have a cardiac depressant effect, slowing heart contractions’ rate or force. They can also reduce systemic vascular resistance, which is the resistance in the circulatory system responsible for blood pressure.

Additionally, when blood pressure changes, the person’s baroreflex response kicks in, and the body begins trying to regulate pressure. This process involves rapidly adjusting heart rate and the constriction or dilation of blood vessels.

This means the various effects of general anesthetic medications can cause large fluctuations in blood pressure.

Fluid imbalance

Surgical procedures can shift the body’s fluid balance and cause high blood pressure after surgery.

When a person receives IV fluids, blood transfusions, or medications during surgery, the amount of fluid in their body significantly increases. This makes it common to experience edema or weight gain after surgery. This fluid overload can also lead to high blood pressure.

Inflammation

Surgery triggers an inflammatory response in the body, which is the immune system’s reaction to an irritant.

When inflammation occurs, the body accumulates plasma and releases leukocytes, or white blood cells, to fight pathogens and repair damage. Small blood vessels enlarge to help the plasma and leukocytes travel to the injury more easily. These processes can affect blood regulation.

Pain level

Surgery often causes pain and stress on the body, leading to an increase in stress hormones such as adrenaline and cortisol. These hormones can elevate blood pressure.

Pain medication

Some pain medications can increase blood pressure. These include nonsteroidal anti-inflammatory drugs such as aspirin, ibuprofen, and naproxen.

High blood pressure typically has no symptoms.

However, if a person’s high blood pressure turns into a hypertensive crisis, they may experience:

If a person experiences these symptoms, they should seek medical attention immediately.

Doctors may prescribe blood pressure medications or antihypertensives to lower high blood pressure and help prevent related complications such as heart attack and stroke.

There are many different generic and brand-name medications for treating high blood pressure, and they each fall into one of the following classes:

Learn more about blood pressure medications.

A doctor may recommend lifestyle modifications to help manage high blood pressure, either in conjunction with medication or as a management tool.

Many modifications relate to dietary adjustments, such as reducing sodium intake and limiting processed foods. Adopting a heart-healthy diet, such as the dietary approaches to stop hypertension diet, has proven beneficial for managing blood pressure.

Other modifications include:

The outlook for people with high blood pressure after surgery varies based on factors such as the individual’s overall health, the extent of the blood pressure elevation, the underlying cause, and how effectively they and their healthcare team manage it.

Postoperative hypertension is common and typically resolves as the body recovers from surgical stress.

Postoperative hypertension is a common physiological response to various surgery-related factors, including anesthesia, inflammation, pain, and even pain medications.

Both people with preexisting hypertension and those with typical blood pressure levels can experience high blood pressure after surgery.

While it usually resolves as the body heals from surgery, monitoring and managing postoperative hypertension is critical for preventing additional cardiac complications.