High blood pressure or hypertension is a symptomless “silent killer” that quietly damages blood vessels and leads to serious health threats.
What is Blood Pressure?
Blood pressure is the force of your blood pushing against the walls of your blood vessels. It is recorded as two numbers and a written as a ratio.
- Systolic: The top number in the ratio, which is also the higher of the two, measures the pressure in the arteries when the heart beats.
- Diastolic: The bottom number in the ratio, which is also the lower of the two, measures the pressure in the arteries between heartbeats.
In order to survive and function properly, your tissues and organs need the oxygenated blood that your circulatory system carries throughout the body. When the heart beats, it creates pressure that pushes blood through a network of arteries, veins and capillaries. This pressure—blood pressure—is the result of two forces: it rises with the first force (systolic) as blood pumps out of the heart and into the arteries. And it falls during the second force (diastolic) when the heart relaxes between beats.
What is High Blood Pressure (Hypertension)?
Hypertension occurs when your blood pressure is consistently too high. High blood pressure (HBP) causes harm by increasing the workload of the heart and blood vessels—making them work harder and less efficiently.
Normal blood pressure for adults is defined as a systolic pressure below 120 mmHg and a diastolic pressure below 80 mmHg. It is normal for blood pressures to change when you sleep, wake up, or are excited or nervous. When you are active, it is normal for your blood pressure to increase. However, once the activity stops, your blood pressure returns to your normal baseline range. Blood pressure also normally rises with age and body size.
Stages of High Blood Pressure in Adults
This chart is a guide for healthy adults. People with diabetes or chronic kidney disease should keep their blood pressure below 130/80 mmHg.
High blood pressure Stage 1
|High blood pressure Stage 2
160 or higher
100 or higher
You may not feel that anything is wrong, but high blood pressure could be quietly causing damage that can threaten your health. The best prevention is knowing your numbers and making changes that matter in order to prevent and manage high blood pressure.
About 85 million Americans (one out of every three adults over age 20) have high blood pressure. And nearly 20 percent don’t even know they have it.
How Does High Blood Pressure Affect Your Health?
Over time, the force and friction of high blood pressure damages the tissues inside the arteries. In turn, LDL (bad) cholesterol forms plaque along tiny tears in the artery walls, signifying the start of atherosclerosis.
The more the plaque increases, the narrower the insides of the arteries become—raising blood pressure and starting a vicious circle that further harms your arteries, heart and the rest of your body. This can ultimately lead to other conditions ranging from arrhythmia to heart attack and stroke. It can also lead to kidney disease as well as blindness.
Hypertension and Stroke
High blood pressure is the single most important risk factor for stroke because it’s the Number 1 cause of stroke.
Similar to a heart attack, most strokes occur when blood vessels in the brain narrow or become clogged, cutting off blood flow to brain cells. This type (ischemic) represents about 87% of all strokes. High blood pressure causes damage to the inner lining of the blood vessels. So this adds to any blockage that is already within the artery wall.
The remaining 13% of strokes occur when a blood vessel ruptures in or near the brain (hemorrhagic). Chronic high blood pressure or aging blood vessels are the main causes of this type of stroke. The force of HBP puts more pressure on the blood vessels until they eventually rupture over time.
Causes of Hypertension
A number of factors and variables can put you at a greater risk for developing hypertension. Understanding these risk factors can help you be more aware of how likely you are to develop high blood pressure.
Common hereditary and physical risk factors for high blood pressure include:
- Family history: If your parents or other close blood relatives have high blood pressure, there’s an increased chance that you’ll get it, too.
- Age: The older you are, the more likely you are to get high blood pressure. As we age, our blood vessels gradually lose some of their elastic quality, which can contribute to increased blood pressure.
- Gender: Until age 45, men are more likely to get high blood pressure than women are. From age 45 to 64, men and women get high blood pressure at similar rates. And at 65 and older, women are more likely to get high blood pressure.
- Race: African-Americans tend to develop high blood pressure more often than people of any other racial background in the United States.
Lifestyle risk factors include:
- Lack of physical activity
- An unhealthy diet, especially one high in sodium
- Being overweight or obese
- Drinking too much alcohol
What can you do to prevent or lower high blood pressure?
Maintain an active lifestyle and exercise at least 30 minutes each day. Get plenty of rest and eat a healthy, low-sodium, high-potassium diet. These are the best ways to affect your blood pressure. When these don’t work, your doctor may prescribe certain medications, such as a diuretic or beta blocker, to help lower your blood pressure.
Talk with your doctor about blood pressure and the risk of heart disease or stroke. If you would like to find a Mercy physician, visit our Find-A-Doctor tool on our website at: www.mercyhealth.org/find-a-doctor.
Sources: National Institutes of Health, American Heart Association
Before you go … check out Mercy Health System’s 2017 Go Red Dance Video to support American Heart Month!
What Is High Blood Pressure? [PDF]
High Blood Pressure and Stroke [PDF]
Why Should I Limit Sodium? [PDF]
What Can I Do To Improve My Blood Pressure? [PDF]
Blood Pressure Log [PDF]
Sodium Tracker [PDF]
High Blood Pressure Risk Calculator
Mercy Health Library: High Blood Pressure
Mercy Health Library: Stroke