People with high blood pressure, or hypertension, have a systolic pressure of 130 millimeters of mercury (mm Hg) or higher, or a diastolic pressure of 80 mm Hg or higher.
The American Heart Association (AHA)Trusted Source state that normal blood pressure readings have a systolic pressure below 120 mm Hg and a diastolic pressure below 80 mm Hg.
High blood pressure often does not cause any noticeable symptoms. However, it can lead to serious health complications, such as heart disease and stroke.
In this article, we outline the distinction between normal and high blood pressure readings and describe the factors that can cause or contribute to high blood pressure. We also provide information on how to treat high blood pressure.
What do blood pressure numbers mean?
Blood pressure readings indicate the force with which the heart pumps blood around the body. These readings take into account two different types of blood pressure: systolic and diastolic.
Systolic pressure measures the degree of blood pressure within the arteries as the heart contracts. Diastolic pressure measures the degree of blood pressure within the arteries as the heart rests between contractions.
Blood pressure monitors display the systolic pressure above the diastolic pressure. For example, the monitor may display the reading 120/80 mm Hg, indicating a systolic pressure of 120 mm Hg and a diastolic pressure of 80 mm Hg.
Blood pressure categories
A healthcare provider will assign a person’s blood pressure reading to one of the following fiveTrusted Source categories (all measurements are in mm Hg):
- Normal: A systolic pressure below 120 with a diastolic pressure below 80.
- Elevated: A systolic pressure of between 120 and 129 with a diastolic pressure below 80.
- High blood pressure (hypertension stage 1): A systolic pressure of between 130 and 139, or a diastolic pressure between 80 and 89.
- High blood pressure (hypertension stage 2): A systolic pressure of 140 or higher, or a diastolic pressure of 90 or higher.
- Hypertensive crisis: A systolic pressure greater than 180, a diastolic pressure greater than 120, or both. A person who is experiencing a hypertensive crisis should consult their doctor immediately.
According to the British Heart Foundation, a blood pressure reading of 90/60 mm Hg or lower indicates low blood pressure.
Blood pressure in different groups
High blood pressure tends to affect certain groups of people more than others. Some examples include those below.
Males
According to a 2015 reviewTrusted Source, males below the age of 65 are more likely to experience hypertension than females belonging to the same age group.
Older adults
Age is an unavoidable risk factor for developing high blood pressure. According to the National Institute on AgingTrusted Source, a blood pressure reading of 130/80 mm Hg or higher would indicate high blood pressure in an older adult.
Isolated systolic hypertension is a type of high blood pressure that results from age-related stiffening of the arteries. It causes a systolic pressure of 130 mm Hg or higher alongside a diastolic pressure below 80 mm Hg. Doctors treat this type of hypertension in the same way that they treat regular hypertension.
People who have overweight
Body weight can play a role in the development of high blood pressure. According to the AHATrusted Source, a person with overweight can decrease their blood pressure by losing as little as 5 or 10 pounds.
For people who have overweight or obesity, losing weight also helps reduce the risk of certain health conditions, including:
Pregnant women
Women can develop high blood pressure during pregnancy. Likewise, individuals with a history of high blood pressure can continue to experience this throughout their pregnancy.
According to the National Library of Medicine, three types of high blood pressure can affect women during pregnancy. They are:
- Chronic hypertension: High blood pressure that developed either before the pregnancy or before the 20th week of the pregnancy.
- Gestational hypertension: High blood pressure that begins after the 20th week of pregnancy. This type is not usually dangerous to the woman or the fetus. Women who develop gestational hypertension usually find that their blood pressure returns to normal within 12 weeks of giving birth.
- Preeclampsia: A rapid rise in blood pressure that is most common during the third trimester of pregnancy. Preeclampsia can damage the kidneys and liver, and it can be life threatening to both the woman and the fetus.
Women should monitor their blood pressure regularly when pregnant. They should talk to their doctor if their blood pressure readings begin to rise or they experience any of the following symptoms of preeclampsia:
- severe headaches
- visual disturbances, such as blurred vision or seeing flashing lights
- pain beneath the ribs
- severe heartburn
- nausea
- vomiting
- a sudden increase in swelling of the face, hands, ankles, or feet
- excessive weight gain due to fluid retention
- feeling very unwell
