Houston Pediatric and Adolescent Hypertension Program

Hypertension - What Is It?

Blood pressure (BP) is determined by measuring the pressure of the blood flowing through your arteries. The measurement of blood pressure concerns just about every one of us at some point in our lives and it is important to be concerned about BP even during childhood. Most visits to the doctor include having a BP measurement performed. Many people perform their own BP measurements as an important part of taking medications or managing lifestyle.

Determining what BP is acceptable and healthy for each individual can be a complicated process. The combination of age, sex, and height will determine what BP level is desirable. When BP is higher than what is considered normal or safe, this is called “Hypertension”.

Can Children Have High Blood Pressure Too?

Yes!! Hypertension also exists during childhood and as much as 5% of the population less than 18 years of age have hypertension. In Houston that means there are between 10,000 and 20,000 hypertensive kids!

What Should You Do?

Knowledge is the best weapon against this silent killer called high blood pressure.

Have your child’s BP measured.

Blood pressure is the measurement of the pressure of the blood flowing through your arteries. The measurement of blood pressure concerns just about every one of us at some point in our life. Most visits to the doctor include having a blood pressure measurement performed. Many people perform their own blood pressure measurements as an important part of taking medications or managing lifestyle. Understanding the importance of the numbers we get from a blood pressure measurement is a challenge for all of us. Determining what blood pressure is desirable for each individual can be a complicated process. It is usually reported as two numbers such as 120/80 mmHg (stands for millimeters of mercury and is a standard way of measuring pressure). The first number is the systolic blood pressure or the highest pressure the heart and vessels can generate. The lower number is the diastolic blood pressure which is the resting pressure of the vessels. Both are important to tell us if someone is at risk for problems.

The course that causes us to develop high blood pressure (hypertension) begins in children, maybe even while still in the uterus. Factors such race and genetic background of hypertension provide a backdrop upon which environmental factors such as stress, weight, smoking, salt intake, medications can act to cause hypertension. Did you know that studies of identical twins that were separated at birth still show the same patterns of blood pressure years later even though they were raised in different families? This is only true though if factors such as diet, stress and weight are accounted for. So both our genetic background and our environment determine if we have hypertension. Our job is to develop ways to determine who will develop hypertension early in life and intervene with lifestyle changes or even medications to prevent hypertension from even starting.

Yes! Hypertension also exists even during childhood and about 1% of the population less than 18 years of age have hypertension. In Houston, Texas, that means that there are between 10,000 to 20,000 hypertensive kids! In the young, hypertension is a little different from adult hypertension in that kids often have a reason to have hypertension like kidney, heart or endocrine problems. This requires a more detailed evaluation of the hypertensive child looking for these causes.

High blood pressure can cause two kinds of damage to your body. First, the high pressure itself can cause your blood vessels and heart to work harder. This causes the heart and vessels to thicken and become stiff and not work well. The thick heart requires more oxygen and can get overworked causing a heart attack. In the brain, the high pressure can cause a blood vessel to burst and cause stroke. It can also cause scarring in the kidney and kidney failure. Secondly, milder hypertension can work as a risk factor with diabetes, smoking, spilling protein in the urine, and high cholesterol to cause atherosclerosis (hardening of the arteries) which can lead to heart attack and stroke.

Yes, using lifestyle changes such as weight loss, exercise, stress reduction and salt restriction and sometimes medications blood pressure can be and should be normalized! This brings the risk of problems from hypertension almost down to if you had normal blood pressure.

No. Blood pressure has wide swings throughout the day and normally can vary by as much as 25%. BP is highest in the early morning when we are getting ready for our day. This is also the time when people most often have their heart attacks or angina. BP becomes pretty stable throughout the day varying with the stress of the day, falls toward evening and drops about 10% while sleeping.

These changes should be taken into account when BP is measured. Some people during a visit to a doctor can have very high BP because of the “stress” of being there. A patient who has high BP in front of a health care professional but has normal BP the rest of the time has white coat hypertension. They may be at risk for developing hypertension some day, but don’t need any tests or therapy now. A new, powerful device called an ambulatory blood pressure monitor (ABPM) can be very helpful in determining BP patterns — particularly those that can lead to end organ damage. Patterns such as hypertension during sleep (nocturnal hypertension), non-dippers (those whose BP does not fall during sleep) and those patient with high variability in BP are all closely associated with end organ damage. Also patients with more than 50% of their BP readings in a day in the hypertensive range (a “BP load” of 50) are at the highest risk for damage. The ABPM is also very useful in the management of therapy of hypertension and in testing the effectiveness of medication to lower BP.

There are home measuring devices sold in stores and many people utilize these devices to perform their own blood pressure checks. Companies such as Spacelabs, Inc. markets a device that is worn constantly. Their ambulatory blood pressure measurement device obtains readings throughout the day and even during sleep. We have a computerized system for analyzing these measurements and providing recommendations to your doctor.

The purpose of this web page is to provide a resource for both the general public and the dedicated doctors and researchers who are interested in the science of measuring and understanding blood pressure. In the coming months you will be able to utilize this site in your search for educational material, for links to other sites containing academic/general public resources, and for contacts in the medical community. Our goal is to gather the energy and knowledge of a diverse group of clinicians, doctors, nurses, teachers, researchers, and businesses and to utilize their strengths towards understanding exactly how blood pressure affects each individual.

Please feel free to visit and use the resources within our website to improve your understanding of blood pressure measurement and importance. Don’t forget to return often as our site grows in size and content over the coming months.