What Is High Blood Pressure?
High blood pressure (HBP) is a serious condition that can lead to coronary heart disease, heart failure, stroke, kidney failure, and other health problems.
"Blood
pressure" is the force of blood pushing against the walls of the
arteries as the heart pumps blood. If this pressure rises and stays high
over time, it can damage the body in many ways.
Overview
About
1 in 3 adults in the United States has HBP. The condition itself
usually has no signs or symptoms. You can have it for years without
knowing it. During this time, though, HBP can damage your heart, blood
vessels, kidneys, and other parts of your body.
Knowing your blood
pressure numbers is important, even when you're feeling fine. If your
blood pressure is normal, you can work with your health care team to
keep it that way. If your blood pressure is too high, treatment may help
prevent damage to your body's organs.
Blood Pressure Numbers
Blood
pressure is measured as systolic (sis-TOL-ik) and diastolic
(di-ah-STOL-ik) pressures. "Systolic" refers to blood pressure when the
heart beats while pumping blood. "Diastolic" refers to blood pressure
when the heart is at rest between beats.
You most often will see
blood pressure numbers written with the systolic number above or before
the diastolic number, such as 120/80 mmHg. (The mmHg is millimeters of
mercury—the units used to measure blood pressure.)
The table below
shows normal blood pressure numbers for adults. It also shows which
numbers put you at greater risk for health problems.
Categories for Blood Pressure Levels in Adults (measured in millimeters of mercury, or mmHg)
| Category | Systolic
(top number) | | Diastolic
(bottom number) |
|---|
| Normal | Less than 120 | And | Less than 80 |
|---|
| Prehypertension | 120–139 | Or | 80–89 |
|---|
| High blood pressure | | | |
|---|
| Stage 1 | 140–159 | Or | 90–99 |
|---|
| Stage 2 | 160 or higher | Or | 100 or higher |
|---|
The ranges in the table apply to most adults (aged 18 and older) who don't have short-term serious illnesses.
Blood
pressure doesn't stay the same all the time. It lowers as you sleep and
rises when you wake up. Blood pressure also rises when you're excited,
nervous, or active. If your numbers stay above normal most of the time,
you're at risk for health problems. The risk grows as blood pressure
numbers rise. "Prehypertension" means you may end up with HBP, unless
you take steps to prevent it.
If you're being treated for HBP and
have repeat readings in the normal range, your blood pressure is under
control. However, you still have the condition. You should see your
doctor and follow your treatment plan to keep your blood pressure under
control.
Your systolic and diastolic numbers may not be in the
same blood pressure category. In this case, the more severe category is
the one you're in. For example, if your systolic number is 160 and your
diastolic number is 80, you have stage 2 HBP. If your systolic number is
120 and your diastolic number is 95, you have stage 1 HBP.
If you
have diabetes or chronic kidney disease, HBP is defined as 130/80 mmHg
or higher. HBP numbers also differ for children and teens. (For more
information, go to
Outlook
Blood
pressure tends to rise with age. Following a healthy lifestyle helps
some people delay or prevent this rise in blood pressure.
People
who have HBP can take steps to control it and reduce their risk for
related health problems. Key steps include following a healthy
lifestyle, having ongoing medical care, and following your treatment
plan.
The
image focuses on high blood pressure in women and explains how high
blood pressure increases the risk of heart disease. An estimated 1 in 3
women has high blood pressure, and the condition is dangerous because it
often causes no symptoms.
The image also contains
a chart showing ranges of blood pressure numbers for normal blood
pressure, prehypertension, stage 1 hypertension, and stage 2
hypertension (also discussed in the text chart earlier in this section).
Finally, the image states that you can take action to prevent high
blood pressure by reducing sodium (salt) intake. Most adults should have
less than one teaspoon, or 1,500 milligrams, of sodium a day. Being
active and maintaining a healthy weight also can help you prevent high
blood pressure.
Sources: National Center for Health Statistics. (2007–2010). National Health and Nutrition Examination Survey;
Centers for Disease Control and Prevention. (2011). Vital signs:
prevalence, treatment, and control of hypertension, 1999–2002 and
2005–2008. MMWR: Morbidity & Mortality Weekly Report, 60(4), 103–108; National Heart, Lung, and Blood Institute, National High Blood Pressure Education Program. (2004). The seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure.
