Average pressure perfusing the organs through the cardiac cycle.
Formula: DBP + (SBP − DBP)/3 — StatPearls: Mean Arterial Pressure.
What does mean arterial pressure mean?
Mean Arterial Pressure (MAP) is the average blood pressure in the arteries during a complete cardiac cycle. It is a more clinically meaningful single number than either systolic or diastolic pressure alone because it represents the actual driving force that pushes blood through the capillary beds of every organ in the body.
The formula, DBP + (SBP − DBP) / 3, weights diastolic pressure more heavily because, at a normal resting heart rate, the heart spends approximately two-thirds of each cycle in diastole (the filling phase) and one-third in systole (the ejection phase). At higher heart rates, diastole shortens relative to systole, so this formula becomes less precise, but it remains widely used due to its simplicity.
MAP is particularly important in critical care medicine. The kidneys require a MAP of at least 65–70 mmHg to maintain filtration; below this threshold, acute kidney injury can develop rapidly. The brain has autoregulation that maintains cerebral blood flow over a MAP range of roughly 50–150 mmHg, but this autoregulation fails in some disease states. Guidelines for septic shock management use a MAP ≥ 65 mmHg as a primary resuscitation target.
Chronically elevated MAP, even when systolic pressure alone appears only mildly raised, accelerates arterial stiffening, left ventricular hypertrophy, and atherosclerosis. Many antihypertensive agents are judged partly on their effect on MAP rather than individual components.
Reference ranges
| Category | MAP (mmHg) | Clinical significance |
|---|---|---|
| Critically low | < 60 | Organ perfusion compromised — emergency |
| Low-normal | 60 – 69 | Borderline; may indicate volume depletion |
| Normal | 70 – 100 | Adequate organ perfusion |
| Elevated | 101 – 119 | Consistent with stage 2 hypertension |
| Hypertensive crisis | ≥ 120 | Requires urgent medical attention |
When should you see a doctor?
A MAP consistently above 100 mmHg warrants medical evaluation and likely treatment. If your MAP is below 65 mmHg and you feel faint, dizzy, or unwell, seek immediate medical attention. Isolated high readings after exercise or stress may not be clinically significant, however, persistent elevation warrants investigation for hypertension and its secondary causes.