In May 2003, the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure (JNC) defined the following categories for blood pressure, based on extensive reviews of scientific literature. The figures are updated periodically to keep pace with new research.
The biggest change is the addition of a new category called prehypertension, which identifies people at higher risk for high blood pressure, heart disease and stroke.
|Category ||Systolic Blood |
Pressure (mm Hg)
| ||Diastolic Blood |
Pressure (mm Hg)
|Normal ||Less than 120 ||and ||Less than 80 |
|Prehypertension ||120-139 ||or ||80-89 |
|Hypertension || || || |
|Stage 1 ||140-159 ||or ||90-99 |
|Stage 2 ||160 or higher ||or ||100 or higher |
To classify your blood pressure, your doctor averages two or more readings. For example, if you have 135/85 mm Hg on one occasion and 145/95 mm Hg on another, your doctor will say you have an average blood pressure of 140/90 mm Hg, which is stage 1 hypertension.
When systolic and diastolic pressures fall into different categories, the JNC advises doctors to rate the blood pressure by the highest category. For example, 150/85 mm Hg is classified as stage 1 hypertension, not as prehypertension.
Systolic hypertension is defined as a systolic pressure of 140 mm Hg or higher and a diastolic pressure below 90 mm Hg.
People in the normal category those with a blood pressure below 120/80 mm Hg have the lowest risk of developing cardiovascular disease. People in the prehypertension category have a greatly increased risk of developing hypertension. These people require lifestyle changes to reduce their risk. People with stage 1 hypertension generally require medication, although aggressive lifestyle changes (in diet and fitness) can sometimes help people avoid the need for medication.
Your doctor might recommend different numbers based on special circumstances, such as:
- Coronary artery disease: 140/90; lower if possible, especially if your symptoms of angina still occur. However, your blood pressure should be reduced gradually. Blood pressure that is lowered too quickly over a short time decreases blood flow in the coronary arteries and stimulates the heart to beat more rapidly. This combination of increased work by the heart muscles with less delivery of oxygen and nutrients can cause more angina symptoms and possibly a heart attack.
- Kidney disease: 125/75, especially if your doctor informs you that protein is spilling in your urine. This is determined by a simple urine test.
- Diabetes (without kidney disease): 130/80
- Pregnancy: Blood pressure normally stays well below 140/90 during pregnancy. Women at risk of preeclampsia or who have chronic diseases, such as diabetes, will have a lower goal below 130/80.