Pulse pressure is the difference between your systolic (top) and diastolic (bottom) blood pressure numbers. If your blood pressure reading is 120/80 mmHg, your pulse pressure is 120 minus 80, which equals 40 mmHg. That 40 mmHg gap is considered normal and reflects how much force each heartbeat generates as it pushes blood through your arteries.
How to Calculate It
The formula is simple: subtract the bottom number from the top number on any blood pressure reading. The top number (systolic) captures the peak pressure in your arteries when your heart contracts and ejects blood. The bottom number (diastolic) captures the lowest pressure between beats, when your heart is relaxing and refilling. The gap between those two values is your pulse pressure.
You can calculate it from any standard blood pressure reading, whether taken at home, in a pharmacy, or at a clinic. Manual and automated blood pressure monitors produce very similar pulse pressure values, with studies showing only about a 2 mmHg average difference between the two methods. So a home monitor works fine for tracking this number over time.
What a Normal Reading Looks Like
A pulse pressure of about 40 mmHg is the standard benchmark for healthy adults, according to Cleveland Clinic. Most clinicians consider anything between roughly 30 and 50 mmHg to be within a healthy range. Below 30 is considered narrow, and above 60 is considered wide. Both extremes can signal underlying problems worth paying attention to.
It’s worth noting that your regular blood pressure numbers might look perfectly acceptable while your pulse pressure tells a different story. Someone with a reading of 150/70, for example, has a pulse pressure of 80, which is significantly elevated, even though neither number in isolation looks alarming in the same way a reading of 180/110 would.
Why Wide Pulse Pressure Matters
A chronically wide pulse pressure, generally above 60 mmHg, is an independent predictor of cardiovascular problems. A large French study found that wide pulse pressure significantly predicted death from heart disease across all age groups and regardless of average blood pressure. In other words, even if your overall blood pressure is under control, a wide gap between those two numbers carries its own risk.
The most common cause is stiffening of the large arteries. When arteries are young and flexible, they stretch to absorb the force of each heartbeat, then gently recoil to keep blood moving between beats. Stiff arteries can’t do this. The systolic number climbs because the arteries don’t absorb the pressure wave, while the diastolic number may drop or stay flat because the arteries don’t spring back effectively. The result is a wider gap.
Less common causes of wide pulse pressure include severe anemia (the heart pumps harder to compensate for fewer red blood cells), an overactive thyroid, and aortic regurgitation, a condition where the aortic valve doesn’t close properly and blood leaks backward into the heart between beats. That backflow lowers diastolic pressure and widens the gap.
What Narrow Pulse Pressure Suggests
A pulse pressure below 25 to 30 mmHg can indicate that the heart isn’t pumping enough blood with each beat. This is called low stroke volume, and it shows up in conditions like heart failure, significant blood loss, and certain types of shock where the body can’t maintain adequate circulation. Severe dehydration can also narrow the gap temporarily by reducing blood volume.
Aortic stenosis, where the valve controlling blood flow out of the heart becomes narrowed, is another classic cause. Because the valve restricts outflow, peak systolic pressure drops while diastolic pressure stays relatively stable, squeezing the gap between them. If you notice your pulse pressure consistently running below 25 mmHg, that’s information worth sharing with your doctor.
How Aging Affects Pulse Pressure
Pulse pressure almost universally widens as people get older. The primary driver is the gradual stiffening of arterial walls. Over decades, the elastic fibers in large arteries like the aorta break down and are replaced by stiffer collagen. Inflammation, atherosclerotic plaques, and changes in smooth muscle tone all accelerate the process.
This is why isolated systolic hypertension, where only the top number is elevated, is the most common form of high blood pressure in middle-aged and older adults. The bottom number may actually decrease with age while the top number rises, creating a progressively wider pulse pressure. Research from the Strong Heart Study of over 3,500 people found that central pulse pressure (measured closer to the heart) is a better predictor of artery thickening, atherosclerosis, and cardiovascular events than standard arm readings.
The widening of pulse pressure with age is so closely linked to arterial stiffness that researchers describe it as a direct surrogate, essentially a simple proxy for how flexible or rigid your blood vessels have become.
Tracking Your Pulse Pressure at Home
If you already monitor your blood pressure at home, you have everything you need. After each reading, subtract the bottom number from the top. Write it down alongside your regular blood pressure log. The trend over weeks and months matters more than any single reading, since pulse pressure fluctuates throughout the day based on activity, stress, hydration, and posture.
Look for patterns. A pulse pressure that’s consistently above 60 or creeping higher over time is a meaningful signal about your arterial health. The same lifestyle factors that improve blood pressure overall, including regular aerobic exercise, limiting sodium, maintaining a healthy weight, and not smoking, also help preserve arterial flexibility and keep pulse pressure in check. Exercise in particular has strong evidence for reducing arterial stiffness, which directly addresses the most common cause of a widening gap.
Pulse pressure isn’t a number most people hear about during routine checkups, but it’s easy to calculate and adds a layer of insight that the standard blood pressure reading alone doesn’t capture. A reading of 120/80 and a reading of 140/100 both produce a pulse pressure of 40, yet they reflect very different cardiovascular situations. Conversely, 150/70 looks less dramatic than 150/100, but that 80-point pulse pressure is the more concerning pattern for long-term heart and artery health.