Blood pressure basics: Blood pressure (“BP”) is usually read by listening with a stethoscope over the artery while slowly deflating a pressurized cuff. Most of the time, the cuff is placed on your upper arm. In the U.S., blood pressure is measured in millimeters of mercury (mmHg) and given as two numbers, such as 120/80 (read as “120 over 80”).



The top number is the systolic pressure and the bottom is the diastolic. The systolic comes from the pressure made by the heart pushing out blood and normally should not exceed 120 mmHg. The diastolic is the pressure inside the arteries between heart beats and normally is 80 mmHg or less.

Blood pressure relates to the interaction of the force of the blood produced by the heart and the size and condition of the blood vessels. Factors that can affect blood pressure include the amount of salt and fluid in your body, the functioning of your kidneys, heart, and nervous system, and levels of certain body hormones.

What is Hypertension? When the systolic blood pressure is consistently 140 mmHg or higher and/or the diastolic pressure is 90 mmHg or higher, you may have hypertension (or “high blood pressure”). Hypertension can affect anyone, including children and adolescents.Worldwide, there are an estimated one billion with hypertension. In the U.S., about one-quarter of the adult population has hypertension or takes blood pressure medicine.

What causes hypertension? Risk factors include smoking, diabetes mellitus, obesity, and close family members with hypertension. Too much salt in your diet can cause high blood pressure. Hypertension caused by a specific and identifiable condition or substance is called “secondary” hypertension. Such causes include: kidney disease, arteriosclerosis (hardening of the arteries), adrenal disease or tumor, sleep apnea, cocaine or amphetamine use, certain medications (including appetite suppressants, certain cold formulations, migraine treatments, birth control pills, and corticosteroids), pregnancy, alcohol abuse, thyroid disease, scleroderma, and others. Hypertension with no defined cause is called “primary” or “essential” hypertension, which is the most common (90% of cases or more).

What are the symptoms of high blood pressure? Unless the pressure gets very high, usually hypertension produces no symptoms (hence the monomer “silent killer”). Symptoms associated with high blood pressure include headache, nose bleed, chest pain, confusion, vision change, fatigue, buzzing in the ear, shortness of breath, and nausea.

How is it diagnosed? Before deciding on treatment, your doctor will need to take your history and perform a physical examination, including checking your BP. Ideally, your doctor should obtain three separate readings about one week apart. If the readings are very high, or if there is evidence of organ damage, your doctor may start treatment on the first visit. Coming to your doctor with blood pressure readings from home can be helpful. Additional testing by the doctor might include blood and urine testing, EKG, chest x-ray, echocardiogram, or kidney ultrasound. Commonly obtained blood testing includes BUN, creatinine, hematocrit, sodium, potassium, calcium, thyroid function, cholesterol, triglycerides,and fasting glucose.

Treatment of hypertension: Lowering the salt in your diet, exercising more, consuming less alcohol, stopping smoking, and losing weight may be sufficient to correct your BP readings. If you have diabetes, work to keep your sugars controlled. Stress management may help for some.

If your doctor decides to give you medicine, there are many different types from which to select. Commonly prescribed general categories of medicines include beta blockers, diuretics, calcium channel blockers, alpha blockers, vasodilators, angiotensin converting enzyme inhibitors, angiotensin receptor blockers, and renin inhibitors. Quite often only one medicine is necessary, but some do require two drugs (often taken as a combination pill) or more. If you cannot tolerate a medicine, or develop an adverse side effect, there are plenty of others to try. It is important to keep taking your medicine even if the blood pressure is normalized by the medicine. Do not stop taking your medicine without your doctor’s approval and guidance.


What are the complications of hypertension? Poorly controlled or uncontrolled high blood pressure can cause damage to the body. It can cause lead to stroke, heart attack, kidney damage or failure, aortic dissection, loss of vision, heart disease or heart failure, blood vessel damage and brain damage. Chronic hypertension can cause the heart to enlarge.

When should I call the doctor? Patients with high blood pressure will usually see the doctor on regularly scheduled appointments. All adults should have their BP checked routinely, even if you have never been diagnosed with hypertension, especially if someone in your family has high blood pressure.

Call your doctor right away if self monitoring shows that your blood pressure remains or suddenly becomes high or you develop severe headache, chest pain, confusion, excessive tiredness, nausea and vomiting, shortness of breath, or vision changes.

Where can I learn more?

American Heart Association
National Heart, Lung and Blood Institute
American Journal of Hypertension
National Institutes of Health