Dr. Robert McClellan, assistant professor of pediatrics at the University of South Alabama College of Medicine, said hypertension – or high blood pressure – in young children is most commonly caused by another medical condition. However, hypertension can also develop for the same reasons it does in adults – being overweight, eating a poor diet, and not exercising.
High blood pressure that occurs on its own, without an underlying condition, is called essential (primary) hypertension. Essential hypertension is increasingly seen in children, according to Dr. McClellan, and should be diagnosed when other causes have been ruled out.
“I always try to rule out renovascular hypertension when seeing a patient with hypertension,” Dr. McClellan said. “Renovascular hypertension is when an artery to the kidney is narrower than it should be, causing the kidney to think it needs more blood pressure. Since the kidney is the primary controller of the body's blood pressure, it releases more signals to the body to increase blood pressure.”
Dr. McClellan said essential hypertension is occurring more frequently in young people as a result of the obesity epidemic. Other risk factors for developing essential hypertension include having a family history of high blood pressure, or being diagnosed with Type 2 diabetes or high cholesterol.
Once diagnosed appropriately, Dr. McClellan said the first step in treating children with essential hypertension is through diet and exercise. If the pressure elevation is concerning, however, then the first step in treatment may also need to include medication.
“About 50 percent of the patients with essential hypertension lower their blood pressure on a low-salt diet,” Dr. McClellan said. “It is a good general practice to limit salt intake.”
Although family history may play a large part in essential hypertension, Dr. McClellan said secondary hypertension may just be bad luck. According to Dr. McClellan, secondary hypertension, or high blood pressure that’s caused by an underlying health condition, is perhaps the most common cause of verified hypertension in children.
“This type of hypertension is caused by something else, like problems with the vessels delivering blood to the kidney,” he said. “Secondary hypertension can usually be treated by figuring out the exact cause.”
Other underlying health conditions that can cause high blood pressure include chronic kidney disease, adrenal disorders, a specific type of tumor, and rarely hyperthyroidism.
High blood pressure could also fit into a third category, called “white coat” hypertension. According to Dr. McClellan, “white coat” hypertension is high blood pressure seen in the clinical setting.
“Seeing your doctor wearing a white coat can make some people anxious, and their blood pressure goes up,” Dr. McClellan said. “This diagnosis should never be assumed without rigorous testing. We are still researching whether or not these patients need medication.”
Dr. McClellan said there are multiple risks to those who have hypertension, including damage to the kidney, heart, and eyes, usually over a long period of time. Also, more immediately, injury to the brain can occur through a stroke.
Dr. McClellan said a child’s blood pressure should be checked every time they are in the doctor’s office. “If a child develops any type of hypertension, they should check their blood pressure at least twice a week,” he said. “If they are on medications, they should take their blood pressure before each dose – usually with a recommendation to not take the medication if it is too low – and call their physician that day.”
To learn more about pediatric hypertension, Dr. McClellan recommends visiting http://www.pediatrichypertension.org/