At What Level is Blood Pressure Too High?



Blood pressure is measured with a blood pressure cuff (sphygmomanometer). This may be done using a stethoscope and a cuff and gauge or by an automatic machine. It is a routine part of the physical examination and one of the vital signs often recorded for a patient visit. Other vital signs include pulse rate, respiratory rate (breathing rate), temperature, and weight.

When discussing blood pressure issues, the health care practitioner may ask questions about past medical history, family history, and medication use, including prescriptions, over-the-counter medications, herbal remedies, and food additives. Other questions may include lifestyle habits, including activity levels, smoking, alcohol consumption, and illegal drug use.

Physical examination may include listening to the heart and lungs, feeling for pulse in the wrist and ankles, and feeling and listening to the abdomen looking for signs of an enlarged aorta. Eye examination with an ophthalmoscope may be helpful by looking at the small blood vessels on the retina in the back of the eyeball.

    * Normal Blood Pressure
          o Systolic less than 120 mm Hg; diastolic less than 80 mm Hg
    * Prehypertension
          o Systolic 120-139 or diastolic 80-89 mm Hg
    * High Blood Pressure
          o Stage 1: Systolic 140-159; diastolic 90-99 mm Hg
          o Stage 2: Systolic more than 160; diastolic more than 100 mm Hg

Blood tests may be considered to assess risk factors for heart disease and stroke as well as looking for complications of hypertension. These include complete blood count (CBC), electrolytes, BUN (blood urea nitrogen), and creatinine and GFR (glomerular filtration rate) to measure kidney function.

A fasting lipid profile will measure cholesterol and triglyceride levels in the blood. If appropriate, blood tests may be considered to look for an underlying cause of high blood pressure including abnormal thyroid or adrenal gland function.

Ultrasound of the kidneys, CT scan of the abdomen, or both may be done to assess damage or enlargement of the kidneys and adrenal glands.

Other studies may be considered depending upon the individual patient’s needs

    * Electrocardiogram (ECG) may help evaluate heart rate and rhythm. It is a screening test to help assess heart muscle thickness. If hypertension is long-standing, the heart muscle has to hypertrophy, or get larger, to push blood against the increased pressure within the arteries of the body.

    * Echocardiogram is an ultrasound examination of the heart It is used to evaluate the anatomy and the function of the heart. A cardiologist is required to interpret this test and can evaluate the heart muscle and determine how thick it is, whether it moves appropriately, and how efficiently it can push blood out to the rest of the body. The echocardiogram can also assess heart valves, looking for narrowing (stenosis) and leaking (insufficiency or regurgitation). A chest X-ray may be used as a screening test to look for heart size, the shape of the aorta, and to assess the lungs.

    * Doppler ultrasound is used to check blood flow through arteries at pulse points in your arms, legs, hands, and feet. This is an accurate way to detect peripheral vascular disease, which can be associated with high blood pressure. It also can measure blood flow in the arteries to both kidneys and sometimes depicts narrowings that can lead to high blood pressure in a minority of patients.