High Blood Pressure (Hypertension)

High blood pressure, also called hypertension, is a condition most often associated with adults. But kids can have high blood pressure too, even as infants.

High Blood Pressure in Kids

An estimated 3% of kids have high blood pressure. In babies, it's usually caused by prematurity or problems with the kidneys or heart. While hypertension is far more common among adults, the rate among kids is on the rise, a trend that experts link to the increase in childhood obesity.

Many kids and teens with high blood pressure have no other health problems but do have a family history of hypertension and an unhealthy lifestyle — a bad diet, excess weight, stress, and insufficient physical activity.

If it goes untreated, high blood pressure can eventually lead to damage to the heart, brain, kidneys, and eyes. But if it's caught early, monitored, and treated, a child with high blood pressure can lead an active, normal life.

Understanding Blood Pressure

Blood pressure is the pressure the blood exerts against the blood vessel walls as the heart pumps. The pressure increases when the heart contracts and pushes blood into the vessels and lowers when the heart relaxes, but there's always a certain amount of pressure in the arteries.

Blood pressure is driven by two physical forces — the one from the heart as it pumps blood into the arteries and through the circulatory system, and the other from the arteries as they resist this blood flow.

Blood pressure changes from minute to minute and is affected by activity and rest, body temperature, diet, emotional state, posture, and medications.

Long-Term Consequences of High Blood Pressure

When someone has high blood pressure, the heart and arteries have a much heavier workload. The heart must pump harder and the arteries are under greater strain as they carry blood. If high blood pressure continues for a long time, the heart and arteries may no longer work as well as they should. Other organs that are receiving the blood, like the kidneys and brain, may also be affected.

Having high blood pressure puts someone at a higher risk for stroke, heart attack, kidney failure, loss of vision, and atherosclerosis (hardening of the arteries).

While high blood pressure doesn't always cause symptoms, it still affects the body and puts a person at risk for those long-term health problems. In rare cases, severe hypertension can cause headaches, visual changes, dizziness, nosebleeds, heart palpitations, and nausea.

If your child has severe high blood pressure and has any of these symptoms, seek medical care immediately.

Measuring Blood Pressure

Doctors measure blood pressure with a sphygmomanometer, which has a cuff that's wrapped around the upper arm and pumped up to create pressure. When the cuff is inflated, it compresses a large artery in the arm, stopping the blood flow for a moment. Blood pressure is measured as air is gradually let out of the cuff, which allows blood to flow through the artery again.

The doctor or nurse will also put a stethoscope over an artery to hear the first pulse as the blood flows through — this is the systolic pressure (or the pressure at the peak of each heartbeat). The diastolic pressure (the pressure when the heart is resting between beats) is noted when the sounds disappear.