Hypertension is high blood pressure. Blood pressure is the force of blood
pushing against the walls of arteries. Arteries are the blood vessels that
carry oxygenated blood from the heart to the body's tissues.
As blood flows through arteries, it pushes against the inside of artery
walls. The more pressure the blood exerts on the artery walls, the higher
the blood pressure is. The size of arteries also affects the blood
pressure. When the muscular walls of arteries are relaxed, or dilated, the
pressure of the blood flowing through them is lower than when the artery
walls narrow, or constricted.
Blood pressure is highest when the heart beats to push blood out into the
arteries. When the heart relaxes to fill with blood again, the pressure is
at its lowest point. Blood pressure when the heart beats is called
systolic pressure. Blood pressure when the heart is at rest is called
diastolic pressure. When blood pressure is measured, the systolic pressure
is stated first and the diastolic pressure second. Blood pressure is
measured in millimeters of mercury (mm Hg). For example, if a
person's systolic pressure is 120 and diastolic pressure is 80, it
is written as 120/80 mm Hg.
The National Heart, Lung, and Blood Institute in Bethesda, Maryland
released clinical guidelines for blood pressure in 2003, lowering the
standard normal readings for adults to less than 120 over less than 80.
Although there are set blood pressure ranges for adults, normal blood
pressure ranges for children vary according to age, gender, and height so
that different levels of growth are considered when evaluating blood
pressure. In children, blood pressure normally rises during growth and
maturation and varies greatly during
Specific systolic and diastolic blood pressure percentiles have been
established for each age, gender, and height group. In children ages six
to 12, up to 125/80 mm Hg is considered normal. In youth ages
12–15, 126/78 mm Hg is normal, and for ages 16–18, 132/82 mm
Hg is normal.
Children whose blood pressure is above the 95th percentile for their
age/gender/height group are diagnosed with hypertension. Children whose
blood pressure is between the 90th and 95th percentile are diagnosed with
pre-hypertension. Adolescents whose blood pressure is greater than 120/80
also may be diagnosed with pre-hypertension.
Childhood hypertension is serious because it increases the risk of heart
, and other medical problems in adulthood. Serious complications can be
avoided by ensuring the child gets regular blood pressure checks and by
treating hypertension as soon as it is diagnosed.
If left untreated, hypertension can lead to the following long-term
Atherosclerosis is hardening of the arteries. The walls of arteries have a
layer of muscle and elastic tissue that makes them flexible and able to
dilate and constrict as blood flows through them. High blood pressure can
make the artery walls thicken and harden. When artery walls thicken, the
inside of the blood vessel narrows. Cholesterol and fats are more likely
to build up on the walls of damaged arteries, making them even narrower.
Blood clots also can get trapped in narrowed arteries, blocking the flow
of blood. When atherosclerosis occurs in the blood vessels leading to the
legs and feet, it is called peripheral vascular disease. Blood flow is
decreased to the legs and feet with peripheral vascular diseases and can
cause poor circulation in the legs, claudication, or aneurysm.
Arteries narrowed by atherosclerosis may not deliver enough blood to
organs and other tissues. Reduced or blocked blood flow to the heart can
cause a heart attack. If an artery to the brain is blocked, a stroke can
Hypertension makes the heart work harder to pump blood through the body.
The extra workload can make the heart muscle thicken and stretch. When the
heart becomes enlarged it cannot pump enough blood. If the hypertension is
not treated, the heart may fail.
The kidneys remove the body's wastes from the blood. If
hypertension thickens the arteries to the kidneys, less waste can be
filtered from the blood. As the condition worsens, the kidneys fail and
wastes build up in the blood. Dialysis or a kidney transplant is needed
when the kidneys fail.
Hypertension can cause damage to blood vessels in the eyes, leading to
retinopathy, or damage to the retina. Retinal damage becomes severe when
blood pressure levels are high and remain elevated for a prolonged period
In the United States, an estimated 5–10 percent of children have
hypertension, and one in four adults (about 50 million) have hypertension.
About 30 percent of those with hypertension do not know they have it.
Hypertension is more common in men than women and in people over age 65
than in younger persons. It also is more frequent and severe in
African-American and Mexican-American adults and children than in white
Americans. The prevalence of high blood pressure among African-Americans
and whites in the southeastern United States
is greater, and death rates from stroke are higher than among those in
In the early 2000s, high blood pressure in children and adolescents is on
the rise. A 2003 report indicated this increase is most likely due to a
greater number of overweight and obese children and adolescents. The U.S.
Centers for Disease Control and Prevention studied the health and
of Americans in the National Health and Nutrition Examination Surveys for
more than 40 years, and the last data were collected in 2000. Researchers
found a trend of high blood pressure in children ages eight to 17 years
who were overweight or obese.
Causes and symptoms
Many different actions or situations can normally raise blood pressure.
Physical activity and changes in position can temporarily raise blood
pressure. Stressful situations can make blood pressure go up. When the
stress goes away, blood pressure usually returns to normal. Certain
medications also may change blood pressure, but usually blood pressure
returns to normal when the drug is discontinued. These temporary increases
in blood pressure are not considered hypertension. A diagnosis of
hypertension is made only when a person has at least three separate high
blood pressure readings performed one to several weeks apart.
Hypertension without a known cause is called primary or essential
hypertension. Although the cause of hypertension is unknown in
90–95 percent of adults, primary hypertension is uncommon in
children, occurring in less than 1–2 percent of hypertensive
When a child has hypertension caused by another medical condition, it is
called secondary hypertension. Secondary hypertension can be caused by a
number of different illnesses. Kidney disease causes hypertension in
80–85 percent of childhood cases. The kidneys regulate the balance
of salt and water in the body. If the kidneys cannot rid the body of
excess salt and water, blood pressure goes up. Kidney infections, a
narrowing of the arteries that carry blood to the kidneys, called renal
artery stenosis, and other kidney disorders can disturb the salt and water
As body weight increases, blood pressure rises. Being overweight or obese
is the strongest predictor of hypertension in young adults.
has steadily increased in children and adolescents over the years. An
estimated 16 percent of school-age children are over-weight. High blood
pressure develops about 10 years after a young person becomes overweight.
Obesity may cause other cardiovascular diseases if it is not managed or
Risk factors are conditions that increase the chance of developing
hypertension. Some of these risk factors can be changed to reduce the risk
of developing hypertension or to lower blood pressure:
is not directly related to high blood pressure in children and
adolescents, those who smoke should stop to reduce their risk of
developing other health problems such as coronary artery disease.
Some risk factors for hypertension can be changed, while others cannot.
Some children inherit a tendency to develop hypertension, and the risk
increases if both parents are hypertensive. Children who have the risk
factors above can work with their doctor and
to manage the controllable risk factors.
Hypertension generally does not cause symptoms. When symptoms occur, they
are usually mild and non-specific. In young children (age three and
younger), symptoms may include:
In older children, symptoms may include:
In severe and acute (sudden-onset) cases, hypertension can cause seizures,
swelling throughout the body, blindness, or renal (kidney) failure. All of
these symptoms require immediate medical attention and
If a child has any of the following symptoms, the parent or caregiver
should call the child's doctor:
If a child has any of these symptoms, the parent or caregiver should
immediately seek emergency medical attention:
Blood pressure in children should be checked regularly: at least at every
doctor's visit after age three. Early detection and treatment of
hypertension improve the child's overall health and decrease the
risk of future health problems associated with hypertension.
Blood pressure is measured with an instrument called a sphygmomanometer. A
cloth-covered rubber cuff is wrapped around the upper arm and inflated.
When the cuff is inflated, an artery in the arm is squeezed to momentarily
stop the flow of blood. Then, the air is let out of the cuff while a
stethoscope placed over the artery is used to detect the sound of the
blood spurting back through the artery. This first sound is the systolic
pressure, the pressure when the heart beats. The last sound heard as the
rest of the air is released is the diastolic pressure, the pressure
between heartbeats. Both sounds are recorded on the mercury gauge on the
The arm cuff used to measure blood pressure in children must be
appropriate to the child's size, or the reading may be inaccurate.
A typical physical examination to evaluate hypertension includes:
The physical exam may include several blood pressure readings at different
times and in different positions. For at least five minutes before the
blood pressure reading is taken, the child should be seated in a chair,
with feet on the floor and arms supported at heart level. For best
results, the child should not eat or drink caffeinated products within the
30 minutes prior to the exam. The physician uses a stethoscope to listen
to sounds made by the heart and blood flowing through the arteries.
During the physical exam, the child's pulse, reflexes, and height
and weight are checked and recorded. Internal organs are palpated to
determine if they are enlarged.
Because hypertension can cause damage to the blood vessels in the eyes,
the eyes may be checked with a instrument called an ophthalmoscope. The
physician will look for thickening, narrowing, or hemorrhages in the blood
Urine and blood tests may be done to evaluate health and to detect the
presence of certain substances that may indicate an underlying condition
that is causing the hypertension.
Usually blood tests and urine tests, along with the physical examination
and medical history, are enough to make the diagnosis of hypertension. If
necessary, to rule out other medical conditions or to assess any damage
from hypertension and/or its treatment, the following tests may be
There is no cure for primary hypertension, but blood pressure can almost
always be lowered with the correct treatment. The goal of treatment is to
lower blood pressure to levels that will prevent heart disease and other
complications of hypertension that could manifest in adulthood. In
secondary hypertension, the disease that is responsible for the
hypertension is treated in addition to the hypertension itself. Successful
treatment of the underlying disorder may cure the secondary hypertension.
Clinicians should work with the child and the parents or caregivers to
develop an individual treatment plan. Specific treatment goals vary.
Treatment should be provided by a pediatric cardiologist or pediatrician
with special knowledge and experience in the treatment of high blood
Depending on the results of diagnostic tests, childhood hypertension is
generally treated with lifestyle changes, including diet and
, before antihypertensive medication is prescribed. Lifestyle changes that
may reduce blood pressure include:
Reaching and maintaining a healthy body weight is important. Overweight
children with hypertension are recommended to lose weight until they are
within 15 percent of their healthy body weight. Even a small amount of
weight loss can make a major difference. Physical activities should be
encouraged, and sedentary activities such as watching television or
should be limited. The recommended exercise goal is aerobic activity,
such as brisk walking, at least 30 minutes per day, most days of the week.
A pediatrician can calculate a healthy range of body weight for the child,
recommend dietary guidelines, and provide activity guidelines to help the
child safely and effectively lose weight. A consultation with a registered
dietitian also may assist the parent or caregiver in implementing dietary
Dietary guidelines are individualized, based on the child's blood
pressure levels and specific needs. In children older than two years of
age, the following low-fat dietary guidelines are recommended:
Elevated blood pressure can be reduced by an eating plan that emphasizes
fruits, vegetables, and low-fat dairy foods, and which is low in saturated
fat, total fat, and cholesterol. The DASH diet is recommended for patients
with hypertension and includes whole grains, poultry, fish, and nuts.
Fats, red meats, sodium, sweets, and sugar-sweetened beverages are
limited. Sodium should also be reduced to no more than 1,500 milligrams
A gradual transition to a heart-healthy diet can help decrease a
child's risk of coronary artery disease and other health conditions
in adulthood. Parents can replace foods high in fat with grains,
vegetables, fruits, lean meat, and other foods low in fat and high in
complex carbohydrates and protein. They can resist adding salt to foods
while cooking and avoid highly processed foods that are usually high in
sodium, such as fast foods, canned foods, boxed mixes, and frozen meals.
Alternative and complementary therapies include approaches that are
considered to be outside the mainstream of traditional health care.
Techniques that induce relaxation and reduce stress, such as
, tai chi, meditation, guided imagery, and relaxation training, may be
helpful in controlling blood pressure. Acupuncture and biofeedback
training also may help induce relaxation. Before learning or practicing
any particular technique, it is important for the parent/caregiver and
child to learn about the therapy, its safety and effectiveness, potential
side effects, and the expertise and qualifications of the practitioner.
Although some practices are beneficial, others may be harmful to certain
Dietary supplements, including garlic, fish oil (omega-3 fatty acids),
L-arginine, soy, coenzyme Q10, phytosterols, and chelation therapy may be
beneficial, but the exact nature of their effects on blood pressure is
unknown. There is little scientific evidence that these therapies lower
blood pressure or prevent the complications of high blood pressure, and
most of these supplements have not been studied extensively in children
Vitamin E and beta carotene supplements were once thought to help prevent
the development of heart disease, but subsequent studies disprove that
Medications usually are not prescribed for children as a first-line
treatment for hypertension. Medications are prescribed, however, to treat
hypertension when the child has significant high blood pressure or organ
damage, or when diet and exercise are not adequately controlling the
child's blood pressure.
Follow-up care for hypertension includes home blood pressure monitoring.
The parent or caregiver checks the child's blood pressure at
different times of the day and records the readings. The doctor reviews
this blood pressure record during the child's check-ups to evaluate
the effectiveness of the child's treatment and to make any
Depending on the child's blood pressure levels and presence of
other medical conditions such as diabetes, the doctor may recommend annual
eye exams to detect the presence of vision changes and the development of
There is no cure for hypertension. However, it can be well controlled with
the proper treatment. Therapy with a combination of lifestyle changes and
sometimes antihypertensive medicines usually can manage blood pressure.
For most children, early primary hypertension causes no immediate risk of
serious health problems, but it does increase the risk for future organ
damage. The key to avoiding serious complications of hypertension is to
detect and treat it at the earliest possible age so that preventive
treatment can be initiated.
Avoiding or eliminating known risk factors helps reduce the risk of
developing hypertension. Making the same changes recommended for treating
hypertension can reduce a child's risk of developing hypertension:
Parents should reinforce with the child that hypertension is a serious
condition that can cause more health problems later in life. Parents
should work with their child to make dietary changes and increase their
activity level to manage hypertension and prevent it from getting worse.
Everyone can benefit when a heart-healthy lifestyle is followed, so the
dietary and activity changes made for the hypertensive child will benefit
the entire family.
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—A weakened area in the wall of a blood vessel which causes an
outpouching or bulge. Aneurysms may be fatal if these weak areas burst,
resulting in uncontrollable bleeding.
—The main artery located above the heart that pumps oxygenated
blood out into the body. The aorta is the largest artery in the body.
—A chronic condition characterized by thickening, loss of
leasticity, and hardening of the arteries and the build-up of plaque on
the arterial walls. Arteriosclerosis can slow or impair blood
circulation. It includes atherosclerosis, but the two terms are often
—A blood vessel that carries blood away from the heart to the
cells, tissues, and organs of the body.
—Referring to the upper chambers of the heart.
—Cramping or pain in a leg caused by poor blood circulation. This
condition is frequently caused by hardening of the arteries
(atherosclerosis). Intermittent claudication occurs only at certain
times, usually after exercise, and is relieved by rest.
Coarctation of the aorta
—A congenital defect in which severe narrowing or constriction of
the aorta obstructs the flow of blood.
—A process of filtering and removing waste products from the
bloodstream, it is used as a treatment for patients whose kidneys do not
function properly. Two main types are hemodialysis and peritoneal
dialysis. In hemodialysis, the blood flows out of the body into a
machine that filters out the waste products and routes the cleansed
blood back into the body. In peritoneal dialysis, the cleansing occurs
inside the body. Dialysis fluid is injected into the peritoneal cavity
and wastes are filtered through the peritoneum, the thin membrane that
surrounds the abdominal organs.
Diastolic blood pressure
—Diastole is the period in which the left ventricle relaxes so it
can refill with blood; diastolic pressure is therefore measured during
—Damage that occurs to the heart when one of the coronary
arteries becomes narrowed or blocked.
—An abnormal accumulation of body fat, usually 20% or more over
an individual's ideal body weight.
—Being 25 to 29 percent over the recommended healthy body weight
for a specific age and height, as established by calculating body mass
—Any disorder of the retina.
—An instrument used to measure blood pressure.
—Interruption of blood flow to a part of the brain with
consequent brain damage. A stroke may be caused by a blood clot or by
hemorrhage due to a burst blood vessel. Also known as a cerebrovascular
Systolic blood pressure
—Blood pressure when the heart contracts (beats).
—The lower pumping chambers of the heart. The ventricles push
blood to the lungs and the rest of the body.
American College of Cardiology.
Heart House, 9111 Old Georgetown Rd., Bethesda, MD 20814–1699. Web
American Heart Association.
7320 Greenville Ave., Dallas, TX 75231. Web site:
American Society of Hypertension.
148 Madison Ave., 5th Floor, New York, NY 10016. Web site:
The Cleveland Clinic Heart Center.
The Cleveland Clinic Foundation, 9500 Euclid Ave., F25, Cleveland, OH
44195. Web site: http://www.clevelandclinic.org/heartcenter.