What is high blood pressure in children?

Blood pressure is the force of the blood pushing against the artery walls. Two numbers are recorded when measuring blood pressure:

• Systolic pressure. This is the higher number. It refers to the highest pressure inside the artery. It occurs when the heart contracts and pumps blood to the body.

• Diastolic pressure. This is the lower number. It refers to the lowest pressure inside the artery. It occurs when the heart relaxes and fills with blood.

For example, if a child's blood pressure is 110/70 mmHg, 110 is the systolic blood pressure and 70 is the diastolic blood pressure.

High blood pressure (hypertension) means that the pressure inside the arteries is too high. This higher pressure may harm the arteries and cause the heart to work harder.

• If the pressure is high when the heart contracts, then the systolic pressure will be high.

• If the pressure is high when the heart relaxes, then the diastolic pressure will be high.

The systolic or diastolic pressure, or both, may be high.

Many things affect blood pressure. These include:

• Time of day. Blood pressure changes throughout the day.

• Physical activity. Blood pressure is usually higher during and right after exercise.

• Emotions. Feeling angry, afraid, or happy can affect blood pressure. Feeling anxious or nervous at the healthcare provider's office may also affect blood pressure.

• Age, height, weight, and gender. Blood pressure is lower in infants compared with older children. Taller children usually have higher blood pressure than shorter children. Overweight or obese children are more likely to have high blood pressure. And boys usually have slightly higher blood pressure than girls.

• Illness or medicines. This might be heart disease or kidney disease.

• Diet. Salt, foods with high salt content (such as packaged meats), alcohol, and drinks with caffeine (such as coffee and soda) can all raise blood pressure.

One high blood pressure reading doesn't mean that your child has high blood pressure. Your child's healthcare provider will want to check your child's blood pressure over a period of days or weeks. When blood pressure stays high, it may be a problem.

What causes high blood pressure in a child?

When the cause of high blood pressure isn't known, it's called primary. Secondary high blood pressure happens with illness or certain lifestyle choices.

Secondary causes of high blood pressure in children and teens include:

• Kidney disease and heart disease

• Prescription medicine such as corticosteroids or birth control pills

• Illegal drugs such as cocaine or methamphetamine

• Endocrine disorders such as overactive thyroid (hyperthyroidism) and diabetes

• Mental health causes such as mental stress and anxiety

Which children are at risk for high blood pressure?

Children and teens are more likely to have high blood pressure if they are:

• Overweight

• Have a family history of high blood pressure or heart disease

• Are boys

• Have a mother who smoked during pregnancy

What are the symptoms of high blood pressure in a child?

High blood pressure often doesn't cause any symptoms. This is why it's often referred to as the silent killer. It's often found during a routine visit to a healthcare provider.

How is high blood pressure diagnosed in a child?

Your child's healthcare provider will diagnose high blood pressure by checking your child's blood pressure. The provider will check blood pressure over several days or weeks before making the diagnosis. Your child's healthcare provider will also:

• Review your child's health history, including diet, exercise, activities, and emotional health

• Review your family history

• Give your child a physical exam

Reliable blood pressure readings taken at home can be helpful in finding out if your child truly has high blood pressure. Ambulatory blood pressure monitoring uses a device that can be worn for 24 hours. It takes multiple blood pressure readings and can help get a more accurate reading of overall blood pressure.

Your child's provider may also order tests. These may include:

• Electrocardiogram (ECG), to check your child's heart rhythm

• Echocardiogram (echo), to check your child's heart anatomy and function as well as any narrowing of the aorta

• Blood tests

• Urine tests

How is high blood pressure treated in a child?

Treatment will depend on your child’s symptoms, age, and general health. It will also depend on how severe the condition is. If your child's healthcare provider has found a secondary cause, such as kidney disease, the disease will be treated. If the provider hasn't found a cause, treatment involves making lifestyle changes. These may include eating a heart-healthy diet that:

• Has lots of fruits and vegetables, whole grains, and low-fat or nonfat dairy products

• Is low in salt

• Limits fatty and sweet foods

Other lifestyle changes may include:

• Losing weight

• Getting more exercise

• Learning to manage emotions and stress

• Quitting or staying away from smoking

• Staying away from alcohol

Many children and teens are able to lower their blood pressure with lifestyle changes. But some children may need medicine. 

What are possible complications of high blood pressure in a child?

High blood pressure may damage the blood vessels and heart. This increases the risk for heart attack and stroke later in life.

What can I do to prevent high blood pressure in my child?

Not all high blood pressure can be prevented. But making heart-healthy lifestyle choices may lower the chance of developing high blood pressure. Help your child:

• Keep a healthy weight

• Eat a healthy diet

• Be active every day

• Stay away from smoking

The American Academy of Pediatrics (AAP) recommends children older than 3 years old have blood pressure screenings at their yearly well-child visit. It should be checked at every healthcare encounter if they are obese, are taking medicine known to increase blood pressure, have kidney disease, diabetes, or a history of aortic arch obstruction or coarctation. Normal blood pressure in kids depends on their gender, age, and height.

When should I call my child's healthcare provider?

If you have a family history of high blood pressure or heart disease, make sure your child's provider knows. And if your child is overweight, make sure you talk with their provider about ways to lose weight.

Key points about high blood pressure in children

• High blood pressure means that the pressure inside the arteries is too high. This may harm the arteries and cause the heart to work harder.

• High blood pressure often has no known cause. Some health conditions and medicines may cause high blood pressure.

• Blood pressure changes. Your child's provider will check it over a period of days or weeks before making a diagnosis of high blood pressure.

• Lifestyle changes like weight loss, exercise, and healthy eating can help to lower high blood pressure.

Next steps

Tips to help you get the most from a visit to your child’s healthcare provider:

• Know the reason for the visit and what you want to happen.

• Before your visit, write down questions you want answered.

• At the visit, write down the name of a new diagnosis and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you for your child.

• Know why a new medicine or treatment is prescribed and how it will help your child. Also know what the side effects are.

• Ask if your child’s condition can be treated in other ways.

• Know why a test or procedure is recommended and what the results could mean.

• Know what to expect if your child does not take the medicine or have the test or procedure.

• If your child has a follow-up appointment, write down the date, time, and purpose for that visit.

• Know how you can contact your child’s provider after office hours. This is important if your child becomes ill and you have questions or need advice.