High blood pressure or hypertension is a situation when the pressure of the blood in a person’s small blood vessels called arterioles is elevated when compared against the blood pressure of a normal or normotensive individual. In adolescents, normal blood pressure values are defined by gender, age and height.
Although high blood pressure may be tolerated for some years in adolescents, eventually damage may occur to the body. When the blood pressure is elevated, then the heart, or pump, must work harder to push the blood through the vessels due to the resistance brought on by the elevated pressure. When the heart works harder, the heart muscle may enlarge and this in itself can cause damage. Persistent high blood pressure may also cause damage to the blood vessels in the kidneys, brain and eyes.
Blood pressure is described by two numbers—the systolic and the diastolic. These numbers refer to the pressure in millimeters (mm) of mercury (Hg). The systolic number represents the pressure in the artery when the heart contracts and pushes out the blood to the body. The diastolic number represents the pressure in the artery when the heart is in the relaxation phase and blood flows back into the heart.
Studies of adolescents by age, height and gender have established normal values for systolic and diastolic pressures. Values that are less than the ninetieth percentile are considered normal; values between the ninetieth and ninety-fifth percentiles are considered high normal and values at the ninety-fifth percentile or higher are considered high blood pressure. According to the National High Blood Pressure Education Program Working Group on Hypertension Control in Children, National Institutes of Health the following are ranges of blood pressure values for adolescents based on age and gender; the values at ninety-five percent are considered to be high blood pressure:
Girls
Age Systolic Blood Pressure Diastolic Blood Pressure
mm Hg mm Hg
12 y 90% 116-122 75-78
95% 120-126 79-82
13 y 90% 118-124 76-80
95% 121-128 80-84
14 y 90% 119-126 77-81
95% 123-130 81-85
15 y 90% 121-127 78-82
95% 124-131 82-86
16 y 90% 122-128 79-82
95% 125-132 83-86
17 y 90% 122-128 79-82
95% 126-132 83-86
Boys
Age Systolic Blood Pressure Diastolic Blood Pressure
mm Hg mm Hg
12 y 90% 115-123 75-79
95% 119-127 79-83
13 y 90% 117-126 75-80
95% 121-130 79-84
14 y 90% 120-128 76-80
95% 121-130 80-85
15 y 90% 123-131 77-81
95% 127-135 81-86
16 y 90% 125-134 79-83
95% 129-138 83-87
17 y 90% 128-136 81-85
95% 132-140 85-89
For adults, normal blood pressure is less than 120 systolic and less than 80 diastoic. Prehypertension is 120-139 systolic and 80-89 diastolic.
The range in each group of values is related to the height percentile of the adolescent. For example, for girls at age fourteen years who are in the fifth percentile of height, the ninetieth percentile for systolic blood pressure is 119 and for girls in the 95th percentile in height, the value is 126. There is a modest effect, therefore, of height on the blood pressure values in teens.
Who is likely to develop high blood pressure?
Approximately one percent to two percent of adolescents develop consistent elevated blood pressure. This is in contrast to the fifteen percent prevalence of high blood pressure in young adults or the sixty percent prevalence in individuals older than sixty-five years. Most adolescents who develop high blood pressure have no underlying cause and this is termed primary or essential hypertension. An underlying disease process such as kidney problems may cause high blood pressure in adolescents. Treating the primary disease process may lower the blood pressure. Teenage girls who take oral contraceptive pills may have a slight increase in their blood pressure, but this should not be extensive enough to cause high blood pressure.
For most of the teens that develop high blood pressure, however, there is no specific cause. Genetic factors play an important part in essential hypertension. Research studies indicate that genes responsible for blood pressure regulation are located on chromosomes thirteen and eighteen. Studies of twins and families indicate a strong correlation between heredity and blood pressure values. Adolescents who are obese have a higher likelihood of developing high blood pressure since more than half of young people with high blood pressure are obese.
There is debate over the issue of salt and high blood pressure. For most teens, there is little correlation with sodium intake and blood pressure. However, in salt sensitive individuals who have high blood pressure, sodium restriction may be beneficial. There is some feeling that African American teens with high blood pressure have a higher likelihood to be salt sensitive.
Individuals who are anxious or depressed seem to have a higher risk for high blood pressure. Anger does not necessarily correlate with high blood pressure, but suppressed anger may be correlated with hypertension.
Adolescents who smoke may have a higher risk for high blood pressure. Interestingly, high blood pressure may increase during the colder months of the years. Lack of exercise and a sedentary life style may lead to elevated blood pressure. This could be related to increasing weight when a teen is sedentary. Also exercise does have value as an outlet for stress and suppressed anger.
What are the symptoms of high blood pressure?
For most adolescents with high blood pressure, there are no symptoms. However, headache may be a symptom for teens with severe hypertension. Dizziness, heart palpitations, easy fatigability and nosebleeds could be associated symptoms. If there is an associated disease such as kidney problems, then there may be symptoms related to that medical problem.
How is high blood pressure evaluated?
The adolescent’s blood pressure should be measured properly on several visits and the values compared to the national norms for gender, age and height. If the values are elevated, then the clinician may begin a diagnostic evaluation that should be tailored to the individual adolescent. A comprehensive history, family history and physical examination should establish a baseline. The purpose of the exam is to look at secondary diseases that may cause elevated blood pressure. The laboratory tests ordered will depend on the individual adolescent. These tests could include urine testing, blood chemistries including lipids and possibly other kidney tests. An electrocardiogram and chest x-ray may be performed to evaluate the size of the heart. Some teens may be referred to a specialist in hypertension, cardiology, endocrinology or kidney disease.
How is high blood pressure treated?
The treatment for high blood pressure consists of non-drug therapy or lifestyle changes and drug therapy. Weight loss is often helpful in reducing blood pressure. For those individuals who are more than ten percent above ideal body weight, then weight loss may be effective in reducing mild high blood pressure to normal. Regular physical exercise may help reduce weight and stress. Some experts feel that regular and moderate aerobic exercise can reduce blood pressure by ten mm.
Experts feel that avoidance of excess salt may reduce blood pressure by between 2.6 to 4.9 mm. Foods high in sodium are often popular with teens. These foods include the following:
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A-1 Sauce
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Soy Sauce
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Corn chips
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Pickles
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Potato chips
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Salted popcorn
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Salted peanuts
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Coke
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Mountain dew
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Hot dogs
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Pizza
Eliminating the use of table and cooking salt in itself may be beneficial. Most salt however, comes in the form of processed or commercial foods that are popular with adolescents.
Any teen with high blood pressure should quit smoking. A few cups of coffee or a caffeinated beverage is probably acceptable on a daily basis. Needless to say, teens should not be drinking alcohol. In adults high alcohol intake may adversely affect the blood pressure.
Stress reduction and psychological therapy may be helpful adjuncts in reducing high blood pressure. Some authors feel that religious faith and activity may be helpful in moderating blood pressure while others feel that transcendental meditation, a relaxation technique may be helpful.
There are many approaches to the pharmacological treatment of high blood pressure. The decision to treat adolescents who have high blood pressure with medication should be done carefully and thoughtfully. The adolescent and his or her family should be involved in and fully informed about the side effects of the medication.
There is no ideal medication for high blood pressure and many experts recommend a step-by-step care program. Medications include diuretics, which cause a reduction of sodium and water in the blood vessels, and this in turns lowers the blood pressure. Side effects include increased urination and possible depression and changes in the sexual drive. Beta-blockers affect the force and frequency of the heart beat thus lowering the workload of the heart. Fatigue, depression, memory loss and vivid dreams may be potential side effects.
Other medications include the angiotensin converting enzyme inhibitors the so-called ACE inhibitors. These medications block the effects of the angiotensin-renin-aldosterone system, which can increase the blood pressure and affect the heart and blood vessels. Some patients report an irritating cough or excessive drop in blood pressure that could be signaled by lightheadedness. Calcium-channel blockers immediately reduce the blood pressure by relaxing the smooth muscle around blood vessels. The resistance in the blood vessels is lowered, so the work of the heart or pump is reduced also. The side effects may include constipation, fatigue or impotence.
How is high blood pressure prevented?
Since most adolescents who have high blood pressure have no disease causing the problem, then prevention will depend on lifestyle changes. These changes include having an appropriate weight for height, a reasonable sodium intake and moderate aerobic physical activity. Stress reduction techniques including yoga may help reduce anxiety and this in turn may lower blood pressure in some individuals. Also, good sleep habits are important. In one study, individuals who had a sleep-deprived night had a higher blood pressure and heart rate the morning after compared to the blood readings the morning after a full night of sleep.
Related topics:
Anger, chronic illness, coffee, depression, diuretics, exercise, headaches, obesity, oral contraceptives, smoking and tobacco, yoga
