man sitting on sofa and measuring his blood pressure

Why High Blood Pressure Is Known as the Silent Killer

May 9, 2023

Medical professionals call high blood pressure, also known as hypertension, the silent killer because it can go undetected for a long period of time and leads to death. Most people who have high blood pressure do not have any symptoms; testing is the only way to determine if someone has it.  

Left untreated, high blood pressure significantly increases the risk of having a heart attack, stroke, brain aneurysm, heart failure, kidney failure, clogged arteries creating blockages in the legs, and dementia.  High blood pressure also can lead to sexual dysfunction and vision problems, including blindness.  

We spoke to cardiologist Marc Eisenberg, MD, to find out why he refers to the condition as “the silent killer.” 

What is blood pressure?    

The heart pumps blood through the arteries—the body’s major blood vessels—and that blood pushes against the artery walls. That pushing is blood pressure.  

How do you know if blood pressure is high, low, or just right? 

When blood pressure is measured, two factors are considered. These two factors are the two numbers that make up a person’s blood pressure. Both are important: 

  1. The top number is the pressure against the arteries when the heart beats (also known as systolic pressure). 
  2. The bottom number is the pressure against the arteries when the heart relaxes between beats (also known as diastolic pressure). 

When the top (systolic) number is greater than 130, a person has hypertension.

When the bottom (diastolic) number is greater than 80, a person has hypertension.  

As people age, both blood pressure numbers tend to increase, due to increased stiffness in large vessels. Just a slight increase in either number significantly increases someone’s risk of death from heart disease or stroke.   

The American Heart Association has five blood pressure ranges:    

  • Normal: Less than 120/80 mm Hg
    • People in this range generally have heart-healthy diets and habits. 
  • Elevated: From 120-129 systolic and less than 80 mm Hg diastolic  
    • People in this range often develop high blood pressure unless diets and habits change. 
  • Hypertension Stage 1: From 130-139 systolic or 80-89 mm Hg diastolic
    • People in this range generally are prescribed lifestyle changes and possibly medication. 
  • Hypertension Stage 2: 140/90 mm Hg or higher 
    • People in this range generally are prescribed both lifestyle changes and medication. 
  • Hypertensive crisis: Higher than 180/120 mm Hg 
    • Individuals require medical attention.  

If you have blood pressure higher than 180/120 mm Hg and are experiencing chest pain, shortness of breath, back pain, numbness/weakness, change in vision, or difficulty speaking, call 9-1-1. 

How do you lower high blood pressure? 

Individuals with elevated blood pressure or hypertension should start to make changes to their lifestyle, including limiting salt in their diet, losing weight if appropriate (even 10 fewer pounds can lower blood pressure by 5 to 10 mm hg), increasing exercise, stopping smoking, and limiting alcohol intake to one to two drinks per day.  

People with cardiac risk factors, such as diabetes, and family history of heart disease will likely be prescribed medication. Taking medicine improves both blood pressure and health outcomes. Talk to a doctor to determine which medication may be best for you.   

What can I do to monitor my blood pressure? 

Go to a doctor and have it checked.    

If your blood pressure is high (or low), your doctor can help figure out why. The majority of people who have high blood pressure inherit it from one or both parents. A doctor can rule out other causes, such as sleep apnea. Many medications, including pain medications, contraceptives, and anti-depressants, can contribute to high blood pressure.  

Being proactive and having your blood pressure tested may save you from the not-so-silent health consequences of having untreated hypertension. Knowing your blood pressure numbers and starting treatment if appropriate are the best ways to stop this silent killer among us.   


Marc Eisenberg, MD, is associate professor of medicine at Columbia University Vagelos College of Physicians and Surgeons, a cardiologist at ColumbiaDoctors and NewYork-Presbyterian, and a member of the Hypertension Center at Columbia University Irving Medical Center. He’s an expert in the accurate diagnosis and treatment of hypertension and evaluating the cardiovascular manifestations of hypertension. He’s the co-author of "Am I Dying," a humorous guide to a variety of health symptoms.