Wide Gap Between Top and Bottom Blood Pressure Numbers
Thomas H. Lee, M.D. - Harvard Health
Q: I'm 72 and my systolic blood pressure has been between 115 and 125 and pretty steady. The diastolic number is low (55-65) and seems to be falling. Is the difference between these two numbers important, and is the falling diastolic number something to worry about?
A: The systolic pressure represents the blood pressure against the vessel walls when the heart is pumping blood. Starting at about age 60, it becomes the most important predictor of cardiovascular problems like stroke and heart disease. You should feel very good about your systolic blood pressure, which is in a fine range.
Diastolic pressure measures the force exerted by blood against vessel walls when the heart is relaxing between beats -- that's why it's the lower of the two blood pressure numbers. With age, our arteries get a little stiff. As a result, they don't stretch out as much every time the heart beats, so more blood gets pushed right on through the larger vessels into smaller ones. Because there's less blood in the large arteries between heartbeats, diastolic pressure tends to decrease.
The difference between these two readings is called pulse pressure. So, in your case, 120 systolic minus 60 diastolic equals a pulse pressure of 60. You can think of pulse pressure as the gap between the peaks (systole) and the valleys (diastole) of your blood pressure.
Older people with stiffer arteries tend to have a wider gap, and thus a higher pulse pressure, usually because the systolic pressure goes up while diastolic pressure stays the same or declines a little. So, in many cases, an increase in pulse pressure amounts to the same thing as an increase in systolic pressure, so doctors tend to focus just on the systolic number.
But you've asked about a gap caused by a stable systolic pressure and a falling diastolic one. That's a little out of the ordinary. It's worth asking your doctor to listen very carefully to your heart to see if your aortic valve is leaking. A leaky aortic valve can cause diastolic blood pressure to fall sharply. Also, it's important to ask that your blood pressure be checked in both arms occasionally. Sometimes blood pressure readings differ between arms because an artery in one arm is blocked.
If your aortic valve is in good shape and you feel fine, I wouldn't be concerned about your current blood pressure readings. I would recommend, though, that you get into a good exercise routine, if you aren't already. Physical activity helps arteries stay nice and supple -- and that will keep your blood pressure readings in the no-worries range.
Thomas H. Lee, M.D. is a professor of medicine at
- Hearing Loss: A Silent Epidemic
- Some Blood Vessels More Prone to Blockages Than Others
- Managing Pain: How to Use Prescription Drugs Without Becoming Addicted
- Another Reason to Get a Flu Shot: To Protect Your Heart
- Banish Hangovers Naturally
- BPPB the Most Common Cause of Vertigo
- Are Isometric Exercises Safe For the Heart
- Healthy Snacks for Children: Choices May Surprise You
- Make Your Own Healthy Breakfast Cereals
- Fitness: Six-Pack Abs for Less
- Solving World Health Issues a Few Dollars at a Time
- Don't Skip Swine Flu H1N1 Vaccine
- Becoming a Vegetarian: Studies Confirm Health Benefits of Meatless Diet
- Everyone's Talking About Mammograms, But Many Women Don't Get Mammograms
- Parents Influence Kids' Relationship With Food
- Diet and Health Can Play Role in Prostate Cancer Risk
- Simple Steps to Managing Stress
- Helpful Tips for Boosting Your Immunity
- Beneficial Bacteria: 7 Amazing Jobs Your Gut Bacteria Do
- Napping May Not be Such a No-No After All
- Preparing Kids - And Yourself - For Their Hospital Visit: 11 Tips
- Recurring, Frequent Headaches in Child Should Prompt Visit to Doctor
- Fitness - Swimming: A Sport For All Seasons
- Prevention for Benign prostatic hyperplasia (BPH)
(c) 2010 Harvard Health Watch