What is hypertension?
Hypertension means “high blood pressure.” This refers to how hard the blood is pushing against the walls of the artery through which it flows—not how quickly it flows. In hypertension, the level of pressure is higher than normal.
How is blood pressure measured?
Blood pressure is measured in millimeters of mercury (mm Hg). A typical normal blood pressure in an adult is 120/80 mm Hg, or "120 over 80." The top number refers to the pressure when the heart is pushing blood out through the arteries (systolic). The bottom number refers to the pressure when the heart is at rest—“between beats” (diastolic).
It’s easy to tell whether an adult has hypertension, because there’s a standard set of measurements:
- Normal blood pressure—systolic < 120 mmHg and diastolic < 80 mm Hg
- Pre-hypertension—systolic 120-139 mmHg or diastolic 80-89 mmHg
- Stage 1 hypertension—systolic 140-159 mmHg or diastolic 90-99 mmHg
- Stage 2 hypertension—systolic ≥160 or diastolic ≥100 mmHg
But it’s harder with children. That’s because there are no universal cut-offs as there are for adults; instead, whether a child has hypertension depends on how his blood pressure compares to his peers (determined by gender, height, and age).
- Pre-hypertension—90th to 95th percentile
- Stage 1 hypertension—95th – 99th (plus 5 mm mercury)
- Stage 2 hypertension—anything higher than 99th plus 5 mm mercury
How common is hypertension in children?
Hypertension is becoming increasingly common in children and adolescents. A recent study that looked at 15,000 adolescents found that nearly one in five had hypertension. And there’s reason to believe that hypertension is vastly underdiagnosed in children, since:
- it can be difficult to measure in infants and young children
- it’s sometimes challenging to identify
- it’s often thought of as not something that really affects kids
The rise in the number of children with primary hypertension in the United States is thought to correlate with the rise of obesity.
What complications are associated with hypertension?
While kids with hypertension are unlikely to have heart attacks and strokes, it still has significant risks. Hypertension causes changes in the structures of the blood vessels and heart. Since hypertension in children has historically been understudied, there isn’t a lot of data about exactly what these changes mean. But we do know that in adults, hypertension increases the chance of complications in the heart, blood vessels, and kidneys. There’s also compelling evidence that some of these changes are seen in children with high blood pressure.
These changes affect:
Blood vessels—high blood pressure can damage blood vessels throughout the body, which makes it harder for organs to work efficiently.
Kidneys—if the blood vessels in the kidneys are damaged, they may stop removing waste and extra fluid from the body. This extra fluid can raise blood pressure even more.
Other organs—if left untreated, hypertension makes it harder for blood to reach many different parts of the body, including the eyes and the brain, and can lead to blindness and strokes.
Can primary hypertension be prevented?
Pediatricians are making great efforts to prevent obesity and stem the tide of problems that accompany it. We believe that promoting healthy lifestyle choices will help combat this trend and will go a long way towards preventing primary hypertension in children (and keep adults healthier, too).
Some things are being done—nutritional information is being made more readily available, there’s one push to provide healthy options in schools and another to remove soft drinks from them—but still, it often comes down to families making the right decisions. We are dedicated to educating families to assist with appropriate dietary and activity choices to improve overall health and reduce the risk of hypertension.
What is “white coat hypertension”?
“White coat hypertension” is when a child’s blood pressure readings are high at the doctor’s office (mostly because she’s anxious, which can cause blood pressure to rise), but normal outside of the office (for example at home or at school).
This is pretty common in kids. By some estimations, between 30 and 40 percent of kids who have high blood pressure in the office actually have white-coat hypertension.
White coat hypertension is still a risk. Everyone’s blood pressure changes from time to time—it’s lower when you’re asleep, for example—but if a child’s blood pressure continually rises when she’s anxious (such as before a test), it can be sign of high blood pressure at other times and potentially cause the same kinds of damage that standard hypertension causes.
White coat hypertension is diagnosed by taking the child’s blood pressure outside of the doctor’s office. This can be done in different ways:
Some parents feel comfortable doing it at home.
Sometimes we make arrangements for a school nurse to check the child’s blood pressure.
Your child’s doctor might recommend that she wear an ambulatory blood pressure monitoring device—a blood pressure cuff attached to a small device that sits on her belt , and measures her blood pressure at regular intervals over the course of 24 hours. This device is about the size of a deck of cards and is usually tolerated very well.
If your child is diagnosed with white coat hypertension, her doctor may still want to follow her, since some children with white coat hypertension will develop actual hypertension in the future.
What causes hypertension in children?
1. Primary hypertension
Primary hypertension means that the hypertension does not seem to be caused by some other underlyng medical condition. Many doctors think that the incidence of childhood or adolescent hypertension has been rising along with the obesity epidemic. The majority of teens and children over age 6 with hypertension have a family history of hypertension and/or are overweight.
2. Secondary hypertension
Secondary hypertension is caused by a known underlying medical condition. Of these, about
- 80 percent of children have some kind of kidney disease or blood vessel abnormalities
- 5 percent have an endocrinological disorder
- 2 to 5 percent have heart disease
Hypertension in infants with hypertension almost always has a secondary cause. In addition, premature infants have a higher incidence of hypertension.
Among kids with hypertension, especially those who are very young, secondary hypertension is more common than primary hypertension. But among children who are older than 6 to 8 years old, the ratio of primary to secondary hypertension is approaching 50/50.
Signs and symptoms
What are the signs and symptoms of hypertension in children?
Often, kids and teens with pre-hypertension or stage 1 hypertension won’t show any symptoms at all. If your child has stage 2 hypertension, she might experience one or more of the following symptoms:
- loss of vision
- chest pain
- abdominal pain
- breathing problems
An infant with stage 2 hypertension may seem irritable, not be feeding properly, or vomiting. Sometimes these infants are diagnosed with “failure to thrive.”
Q: If left untreated, does hypertension get worse?
A: It’s hard to say. Researchers are starting to see that kids and adolescents with pre-hypertension are more likely to develop stage 1 hypertension, but we don’t know if or when stage 1 hypertension will progress to stage 2.
Q: Can hypertension be cured?
A: In some cases, secondary hypertension can be “fixed.” For example, if:
- it’s caused by a narrowing in a blood vessel that the doctors are able to widen
- it’s caused by a rare endocrine tumor that doctors are able to treat successfully
There are also cases in which hypertension might be transient; for example, if it’s caused by a temporary inflammation of the filters in the kidney.
Even when hypertension can’t be “fixed,” it can almost always be well-controlled, with diet and exercise and/or medication.
Q: If my child is being treated for hypertension, what should I watch out for?
A: Keep an eye out for:
- chest pains
- severe headaches that don’t seem to respond to at-home treatment
- changes in vision
- swelling of hands and feet
- shortness of breath with limited exertion
- changes in her urine (such as lack of urine production, urine that is brown or tea-colored)
Call your child’s doctor if she experiences any of these symptoms.
Q: Will my child need to go on medication?
A: Only a fraction of kids with hypertension require medication. Frequently, it’s treated with diet and exercise modification first. And if the child is overweight, every kilogram (around 2 pounds) of weight she loses, her blood pressure could bring her blood pressure down by about a point.
Q: Will my child have hypertension as an adult?
A: While children with hypertension are more likely to have it as adults, it’s not necessarily always the case. This depends on factors including the cause of the hypertension and how it responds to treatment.
Q: What is the most common treatment?
A: For children with pre-hypertension or stage 1 hypertension, changing to a more healthful diet and exercising more is often enough to manage the hypertension. For children with more severe hypertension, medication is often necessary.
Q: If my child is taking medication for hypertension, will she have to take it for the rest of her life?
A: Not necessarily. If your child has primary hypertension, appropriate lifestyle modifications may allow for medications to be stopped. In addition, if a secondary cause is identified and successfully treated, medications may not be necessary.