The standard definition of high blood pressure is determined by the Joint National Committee (JNC) on Detection, Evaluation, and Diagnosis of High Blood Pressure. A person is considered to have high blood pressure after three to six elevated blood pressure measurements over several months. These definitions apply to adults who are healthy and not using medication for high blood pressure. If the two pressures fall in different categories, the higher one is used to determine the severity of the hypertension.
Normal blood pressure - Systolic <120 mmHg AND diastolic <80 mmHg
Prehypertension - Systolic 120 to 139 mmHg OR diastolic 80 to 89 mmHg
The term prehypertension was chosen because patients with blood pressures in this range are at increased risk of progressing to hypertension and developing cardiovascular complications.
Stage 1: systolic 140 to 159 mmHg OR diastolic 90 to 99 mmHg
Stage 2 : systolic ≥160 mmHg OR diastolic ≥100 mmHg
Most adults with hypertension have essential or primary hypertension, which means that the cause of the high blood pressure is not known. A small subset of adults have secondary hypertension, which means that there is an underlying and potentially correctable cause.
High blood pressure does not usually cause any symptoms.
Treatment and drugs
Un-treated hypertension can lead to a variety of complications, including heart disease and stroke. The risk of these conditions increases as blood pressure rises above 110/75, which is still in the healthy range.
Benefits of treatment - In multiple studies of people with hypertension, those who were given blood pressure lowering medications for four to five years had a significant reduction in the number of coronary events, stroke, and death compared to those who did not receive treatment.
Lifestyle changes - Treatment of hypertension usually begins with lifestyle changes. Making these lifestyle changes involves little or no risk. Recommended changes often include a moderate restriction on salt in the diet, weight loss in those who are overweight or obese, avoiding excess alcohol intake, stopping smoking, and regular aerobic exercise.
Medication - Antihypertensive medication is usually recommended when the blood pressure is consistently at or above 140/90 mmHg. Treatment with medication is recommended at a lower blood pressure (usually 130/80 mmHg) for people with diabetes or chronic kidney disease.