Blood pressure is a measurement of the pressure of blood within the arteries. A reading records two values; systole is the maximum pressure when the heart beats and diastole is the minimum arterial pressure between heart beats. Normal (resting) blood pressure should ideally be below 130/85 mmHg. A resting blood pressure between 130/85 and 139/90 mmHg is considered to be high-normal and anything over 140/90 is considered to be hypertension (high blood pressure). To diagnose hypertension an individual must present with a blood pressure of 140/90 on a number of occaisions, as a single high reading could be due to anxiety, stress or exertion prior to the exam and the measurement may therefore not reflect the person's true resting blood pressure.
| Example blood pressure measurement: | |
|---|---|
| Systolic (mgHg) |
120 |
| Diastolic (mgHg) |
80 |
| (Pulse pressure) | 40 |
Normal values[]
This is a list of normal arterial blood pressure ranges;
| Category | Systolic (mmHg) | Diastolic (mmHg) |
|---|---|---|
| Optimal | <120 | <80 |
| Normal | <130 | <85 |
| High-normal | 130-139 | 85-89 |
| Grade 1 hypertension (mild) | 140-159 | 90-99 |
| Subgroup (borderline) | 140-149 | 90-94 |
| Grade 2 hypertension (moderate) | 160-179 | 100-109 |
| Grade 3 hypertension (severe) | >180 | >110 |
| Isolated systolic hypertension | >140 | <90 |
| Subgroup (borderline) | 140-149 | <90 |
Pulse pressure[]
Pulse pressure is the difference between systolic and diastolic blood pressure, and at rest should ideally be around 40mgHg.
A high pulse pressure (e.g. 60 or 80mgHg) could either be the result of stiffening of the arteries (which occurs naturally with age) or could be due to aortic regurgitation - many of the symptoms and signs of aortic regurgitation are the result of the increased pulse pressure that accompanies it. A pulse pressure lower than 40mgHg is probably the result of a measurement error - if however, it is genuinely reduced the cause could be the result of decreased cardiac output due to heart failure, hypovolemic shock or another similar condition.
See also[]
- Heart rate
- Hypertension
- Hypertensive crisis
- Vital signs
