You may have masked hypertension if you have normal blood pressure readings in the doctor’s office, but high blood pressure readings at home. Monitoring your blood pressure at home can help you recognize this condition.

Hypertension is defined by the Centers for Disease Control and Prevention (CDC) as a blood pressure reading at or above 130/80 mmHg. Nearly half of adults in the United States live with this condition or are taking hypertension medications.

But for some people, these numbers will only appear on blood pressure readings outside of the doctor’s office.

Known as masked hypertension, it can be difficult to recognize hypertension when it’s not showing up in medical check-ups. This article will discuss why masked hypertension occurs, what risks high blood pressure poses, and how you can recognize and treat it.

Masked hypertension is when you may have a normal blood pressure reading at the doctor’s office and a higher reading when at home or in other everyday environments.

By comparison, regular hypertension means that someone has high blood pressure that occurs in many scenarios, no matter the location — including at the doctor’s office or shown in medical checks.

There’s also something known as white coat hypertension, which is the opposite of masked hypertension. White coat hypertension can cause inaccurate blood pressure readings when someone is in a medical environment and normal blood pressure readings when they’re in other places.

An estimated 10 to 40% of people have masked hypertension, according to this 2018 study. That prevalence depends on blood pressure readings during the day and when asleep, as well as slightly varying criteria as determined by experts in Europe versus the United States.

Some people with masked hypertension may experience symptoms that include:

  • dizziness
  • facial flushing
  • blood spots in the eyes

But people with high blood pressure often have no signs or symptoms. Even without symptoms, doctors may suspect that you have masked hypertension if lab tests reveal damage to the kidneys or heart.

Doctors may also suspect masked hypertension when certain risk factors — family history, smoking, etc. — are present.

The exact cause of masked hypertension is unknown.

But research shows it’s more common in people who smoke and those who drink excessive amounts of alcohol. Masked hypertension is also more common in men and people with diabetes.

You may suspect masked hypertension if you have risk factors like family history of hypertension in both parents, a prior history of high blood pressure, or multiple cardiovascular risk factors.

These are important to consult with your healthcare team on so they know the risks and can consider the possibility of masked hypertension.

Advances in home blood pressure monitors have made it easier for individuals to track their own blood pressure at home and determine if they have high blood pressure outside of the doctor’s office.

If your doctor suspects masked hypertension or home blood pressure records show high blood pressure, they may perform further testing to confirm this, identify potential underlying causes, and determine the extent of any damage high blood pressure may have caused to the heart and kidneys. This testing may include:

Some research shows masked hypertension is more common in those with diabetes. Additionally, hypertension is commonly associated with diabetes, and many of the risk factors for the two conditions overlap.

Diabetes can scar the kidneys, which can lead to salt and water retention, increasing blood pressure. Diabetes can also damage small blood vessels over time, causing their walls to stiffen and not properly function, further contributing to high blood pressure.

Lifestyle changes and medications may help to control hypertension.

Some lifestyle changes your doctor may suggest include:

Your doctor may suggest medications, including:

Advances in home blood pressure monitoring have helped people to identify their masked hypertension.

If you have hypertension, it’s important to talk with your doctor about treatment options. Untreated high blood pressure can cause a heart attack or stroke. It can also damage organs like the heart and kidneys.