Children’s health: Understanding blood pressure readings in children

At most well-child visits, parents expect to hear about height and weight. But another important number is quietly becoming part of routine care: blood pressure.

While many people think of high blood pressure as an adult problem, doctors say it is showing up more often in children and teens.

“The good news is that when we catch it early, there is a lot we can do to improve it,” said Dr. Kendra Ward, pediatric cardiologist and director of the Cardiopulmonary Exercise Lab, Cardiac Rehabilitation program and Preventative Cardiology program at Lurie Children’s.

Why blood pressure checks start early

Doctors begin checking blood pressure at age 3 during yearly physicals. For some younger children — such as those born prematurely or with heart or kidney conditions — screening may begin even earlier.

Blood pressure measures how hard blood pushes against the walls of the arteries. The top number, called systolic pressure, shows the force when the heart beats. The bottom number, diastolic pressure, measures the force when the heart rests between beats.

In adults, a reading below 120/80 is considered normal. In children, it is more complex. Normal ranges vary based on age, height and sex. Still, experts say blood pressure in kids should generally stay below 120/80, and anything consistently higher needs attention.

One high reading does not mean a child has hypertension. Doctors must see elevated numbers on three separate visits before making a diagnosis.

“Sometimes kids are nervous at the doctor’s office, and that alone can raise their blood pressure,” said Dr. Ward. “We call this ‘white coat hypertension.’ That’s why we take repeat measurements and sometimes ask families to monitor at home.”

Why blood pressure might read high

Temporary spikes in blood pressure can happen for many reasons. Anxiety, recent exercise, talking during the test, or even using the wrong cuff size can affect the reading. Caffeine, lack of sleep and stress can also cause short-term increases.

If readings stay high over time, doctors look more closely.

There are two main types of high blood pressure in children.

Primary, or essential, hypertension has no single medical cause. It is more common in older children and teens and is often linked to lifestyle factors such as excess weight, high salt intake, low physical activity and family history.

Secondary hypertension is caused by another health condition. It is more common in younger children and may be related to kidney disease, heart defects, hormone problems or certain medications.

“Identifying the cause is important because it guides how we treat it,” said Dr. Alexander Kula, pediatric nephrologist at Lurie Children’s said. “In younger children especially, we want to be sure there isn’t an underlying condition driving the high numbers.”

Why it matters

High blood pressure in childhood can track into adulthood. Over time, it increases the risk of heart disease, stroke and kidney problems.

“The earlier we intervene, the better the long-term outlook,” said Dr. Kula. “In many cases, especially when we address lifestyle factors, blood pressure can return to a healthy range.”

What parents can do

The first step is simple: make sure your child’s blood pressure is checked at every annual visit.

If it runs high, lifestyle changes are often the first line of treatment. Most children do not need medication right away.

Healthy eating plays a major role. Experts recommend focusing on fruits and vegetables, whole grains, lean proteins and low-fat dairy products. Cutting back on salt and processed foods can make a significant difference. Sugary drinks, including soda and sports drinks, should be limited or replaced with water.

Physical activity is just as important. Children should aim for at least 60 minutes of movement each day. That could include sports, playground time, biking, dancing or family walks.

“Regular activity strengthens the heart and helps maintain a healthy weight,” Ward said. “It doesn’t have to be complicated. The key is finding something your child enjoys.”

Sleep and stress also matter. Poor sleep habits and chronic stress can contribute to elevated blood pressure. Parents should encourage consistent bedtimes and limit screen use before bed. If a child snores loudly or seems very anxious or overwhelmed, it is worth discussing with a pediatrician.

In some cases, doctors may recommend home blood pressure monitoring. Families should use an automatic arm cuff that fits the child properly. Keeping a log of readings helps doctors spot patterns and determine whether blood pressure is truly elevated or just higher in the office setting.

A manageable condition

Ultimately, experts assure that high blood pressure in children is often manageable, especially when caught early.

“With the right support, most kids can improve their numbers and protect their long-term heart health,” Ward said. “Parents should not panic, but they should take it seriously.”

By paying attention to this often-overlooked vital sign, families can take simple steps now that may help prevent serious health problems later.

• Children's health is a continuing series. This column was provided by Ann & Robert H. Lurie Children's Hospital of Chicago.