Q.What is a normal resting blood pressure for an adult, and at what reading is hypertension diagnosed?

Blood pressure is recorded as two numbers: systolic pressure (when the heart contracts) over diastolic pressure (when the heart relaxes), measured in millimeters of mercury (mm Hg).

Normal resting blood pressure for an adult is considered to be around 120/80 mm Hg or lower. Readings in this range indicate that the cardiovascular system is functioning efficiently without excessive force on arterial walls.

Hypertension (high blood pressure) is diagnosed when readings consistently reach or exceed 140/90 mm Hg. This threshold marks the point at which the sustained elevation in pressure begins to pose significant health risks — damage to blood vessels, increased strain on the heart, and heightened risk of stroke, heart attack, and kidney disease. A single elevated reading does not confirm hypertension; the diagnosis requires repeated measurements over time to rule out temporary spikes from stress, activity, or anxiety. …

Blood pressure measures the force your blood exerts against artery walls as your heart pumps. It's recorded as two numbers: systolic pressure (the higher number, when the heart contracts) over diastolic pressure (the lower number, when the heart relaxes between beats). Both are measured in millimeters of mercury, abbreviated mm Hg.

For a healthy adult at rest, blood pressure typically sits near 120/80 mm Hg. This is often called the "normal" or "optimal" range. The systolic reading of 120 reflects the peak pressure during a heartbeat, while the diastolic 80 represents the baseline pressure maintained in your arteries when the heart is filling.

The Hypertension Threshold

Hypertension—chronic high blood pressure—is diagnosed when readings consistently meet or exceed 140/90 mm Hg. The word "consistently" matters here: a single elevated reading during stress or after exercise doesn't constitute hypertension. Diagnosis requires multiple measurements taken on different days, ideally at rest, to confirm the pattern.

Why this threshold? Sustained pressure at or above 140/90 significantly increases the workload on your heart and damages blood vessel walls over time. This elevates the risk of heart attack, stroke, kidney disease, and other cardiovascular complications. The diagnostic line is drawn where the health risks become clinically significant.

The Range Between Normal and Hypertension …