What is high blood pressure?

Hypertension or high blood pressure occurs when the pressure caused by the flow of blood through arteries is too high. An alarming 1 in 3 American adults (79 million people) have high blood pressure. High blood pressure is sometimes called the “silent killer” because it usually does not have any symptoms but when left untreated can be deadly. If left untreated, high blood pressure over time may lead to heart disease, stroke, kidney disease, hardening of the artery walls (arteriosclerosis), vision loss, sexual problems, and fluid in the lungs. Some of these conditions are threatening. Therefore, it is important to diagnose high blood pressure early and receive appropriate treatment to prevent future complications. 

Understanding blood pressure readings

Blood pressure in measured in millimeters of mercury (mmHg) and the two pressures measured are systolic and diastolic. The top numbers refers to the systolic blood pressure which is the pressure inside the arteries when the heart contracts to push blood out of the heart. The bottom number is the diastolic pressure which represents the pressure in the arteries when the heart is filling with blood (relaxed). It is important for all everyone to understand what blood pressure numbers mean. 

Normal blood pressure

systolic pressure less than 120 mmHg or

diastolic pressure less than 80 mmHg

At risk or prehypertension

systolic pressure between 120-139 mmHg or

diastolic pressure between 80-90 mmHg

High blood pressure

systolic pressure 140 mmHg or higher or

diastolic pressure 90 mmHg or higher

How is high blood pressure diagnosed?

The American Heart Association recommends screening patients at regular healthcare visits or at least once every 2 years. In the healthcare setting blood pressure is easily measured by an instrument called a sphygmomanometer. A blood pressure cuff is wrapped around the upper arm and inflated quickly followed by slow release of the pressure. If blood pressure is higher than normal, your doctor may require you to come back on a separate day for another reading. Patients with higher than normal blood pressure reading may also be asked to monitor their blood pressure at home before a diagnosis is made. Patients may purchase easy to use automatic blood pressure machines which provide blood pressure readings within minutes. Hypertension can only be diagnosed by your doctor and a diagnosis of high blood pressure is done by taking the average of two or more blood pressure readings taken on separate days.

More information on how to monitor and record your blood pressure can be found on the American Heart Association Website. 

Risk factors for developing high blood pressure

Although anyone can develop high blood pressure, several factors may increase a person’s risk.

Race or ethnicity

The occurrence of high blood pressure is highest in African Americans. 

Age

Blood pressure is known to increase with age and hypertension is more common in adults and the elderly. 

Gender

Males are more likely to develop high blood pressure than women until age 45. Between ages 45-64, men and women are equally likely to have hypertension.  Beyond age 64 women are at higher risk. 

Life Style

Eating a diet high in salt, drinking too much alcohol, physical inactivity, and smoking increase the risk for hypertension.

Other Conditions

Diabetes and obesity also increase the risk of high blood pressure. 

What are the signs and symptoms of high blood pressure?

As mentioned earlier, hypertension is called the “silent killer” because most patients do not have any symptoms. Most people do not know they have high blood pressure until their blood pressure is measured by their doctor, pharmacist or other healthcare professionals. Therefore, it’s important for everyone to regularly visit their doctor and have their blood pressure checked. You can also check your blood pressure while at the pharmacy.

General approach to high blood pressure treatment

The main goal of high blood pressure treatment is to reduce hypertension related complications and death. For most patients below the age of 60, the goal of treatment is to reduce blood pressure to less than 140/90 mmHg. The goal blood pressure in patients age 60 years and older without diabetes or chronic kidney disease is less than 150/90 mmHg. The goal blood pressure in diabetes or chronic kidney disease regardless of age is less than 140/90 mmHg.

Treatment is usually started with one high blood pressure medication in patients younger than 60 years of age whose systolic pressure is persistently ≥ 140 mmHg and/or the diastolic pressure is persistently ≥ 90 mmHg. For patients who are 60 years and older, single medication treatment is started if the systolic pressure is persistently ≥ 150 mmHg and/or diastolic pressure is persistently ≥ 90 mmHg.

Use of two medications is usually considered in patients whose baseline blood pressure is ≥ 160 mmHg. Additionally, all patients should make appropriate lifestyle changes to control their blood pressure. 

Life style modifications that have beneficial effects on lowering BP include:

Maintaining healthy body weight: overweight patients can experience significant reductions in their blood pressure by losing as little as 10 pounds or 4.5 kg.  The decrease in blood pressure with weight loss usually ranges from 0.5 to 2 mmHg for every 1 kg of body weight lost.

Eating a heart healthy diet: The Dietary Approaches to Stop Hypertension (DASH) diet recommends eating lots of fruits, vegetables, low-fat dairy products, and decreasing intake of saturated and total fats. Here is more information on the DASH diet.

Limiting the intake of salt or sodium: patients who already have high blood pressure can benefit from limiting their intake of salt to 1.5 g/day. In randomized clinical studies moderate sodium reduction has been shown to decrease blood pressure by 4.8/2.5. 

Limiting the intake of alcohol: drinking too much alcohol may cause or worsen high blood pressure. Men should limit their alcohol intake to 2 drinks per day while women should limit their consumption to 1 drink per day.

 Exercising regularly: most adults should exercise at least 30 minutes on most days of the week.

Stop smoking

Starting hypertension treatment in most patients

The main classes of drugs that are preferred first line agents for the initial treatment of hypertension in most patients include thiazide type diuretics, calcium channel blockers (CCBs), ACE inhibitors (ACEIs), and angiotensin II receptor blockers (ARBs). Clinical studies have shown that each of these four classes of medications are equally effective in reducing blood pressure. Furthermore, these agents have evidence of reducing cardiovascular risk in clinical trials.

Patients who fail to respond or respond poorly to initial treatment with first line agents may benefit from higher doses or combinations of first line agents. Alternative treatment options include beta blockers, alpha blockers, loop diuretics, aldosterone antagonist, peripherally acting adrenergic antagonists, alpha1/beta blockers, central alpha 2 adrenergic antagonists, and direct vasodilators.

Regardless of the treatment option, all blood pressure goals should be reached within one month of starting treatment. If a patient’s blood pressure is not at goal after 1 month of treatment, clinicians are advised to increase of the dose of the current medications or consider adding another agent to the existing regimen.

References and Resources

Know the Facts About High Blood Pressure. Centers for Disease Control and Prevention CDC.  

DiPiro J, Talbert R, et al.  Pharmacotherapy: A Pathophysiologic Approach, 9^th edition.  Chapter 3. Hypertension.  

Kaplan N MD.  Overview of hypertension in adults.  In UpToDate.  

Kaplan N MD, Calhoun D MD.  Treatment of resistant hypertension.  In UpToDate.  

Mann, J MD.  Choice of therapy in primary (essential) hypertension: Recommendations.  In UpToDate.