What time of day is your blood pressure the lowest

MONDAY, Nov. 2, 2020 (HealthDay News) -- If your blood pressure changes a lot overnight -- either rising or falling -- you may have an increased risk of heart disease and stroke, a new study from Japan reports.

When systolic blood pressure (the top number) jumps up by 20 mm/Hg or more during the night, the risk of heart disease and stroke goes up by 18% and the risk of heart failure increases by 25%.

If people consistently had higher blood pressure readings at night, but normal readings during the day, the risk of heart failure more than doubled. The researchers, writing in the journal Circulation, dubbed this a "riser pattern."

On the other hand, for people with a drop in blood pressure of more than 20%, the study team noted a more than twice the risk of stroke. They called this group "extreme dippers."

"Nighttime blood pressure is increasingly being recognized as a predictor of cardiovascular risk," study lead author Dr. Kazuomi Kario said in a journal news release. He's chair of cardiovascular medicine at the Jichi Medical University in Tochigi, Japan.

Dr. Raymond Townsend, an expert volunteer for the American Heart Association, said blood pressure is typically higher in the morning and lower in the afternoon and evening.

Compared to the overall daytime blood pressure pattern, "blood pressure is generally about 10% to 20% lower during sleep. Sleep time offers a relatively pure look at blood pressure. Most factors that influence blood pressure are minimized during sleep," he explained.

But health care professionals usually rely on in-office blood pressure measurements taken during the day to diagnose high blood pressure and to figure out whether or not a blood pressure medication is working or not, the researchers said. These daytime measurements may miss high blood pressure that happens at night. They can also miss big dips in blood pressure.

Dr. John Osborne, director of cardiology at State of the Heart Cardiology in Dallas, said, "When we measure blood pressure in the office, we're mainly getting daytime blood pressure. Seeing what happens at night can give us a much deeper insight."

Osborne said this study "is another signal that we really need to incorporate ambulatory blood pressure monitoring into the evaluation of high blood pressure. If we only see blood pressure during the day, it dramatically reduces our ability to assess overall risk."

Ambulatory blood pressure monitoring allows doctors to see blood pressure levels over a 24-hour period, according to the American Academy of Family Physicians. Patients are fitted with a blood pressure cuff and sent home with a portable monitor that automatically inflates at regular intervals. The machine also records each blood pressure reading it takes in a day.

The current study included more than 6,300 Japanese adults. Their average age was 69. Almost half were men, and more than three-quarters were on blood pressure lowering medications. The average follow-up time was four years.

During the study, volunteers had 20 daytime and seven nighttime ambulatory blood pressure monitor readings.

So should everyone with high blood pressure get their nighttime blood pressure checked, too?

"The best answer right now is maybe. Keep in mind these were people with some existing cardiovascular disease risk factors [already]," Townsend explained. They were also all Japanese, and the findings might not be generalizable to other populations.

And, though it seems to be slowly changing, reimbursement for ambulatory blood pressure monitoring can be tough to get, Townsend said.

But, he added, "The take-home for me is that there is information available about an individual in their nighttime blood pressure patterns."

Both Townsend and Osborne said changing the timing of blood pressure medications might help, but there's not enough data to say for sure if it would. Both said more research is needed.

More information

Want to check your blood pressure at home? Visit Validate BP, a website from the American Medical Association that checks commercially sold blood pressure monitors to make sure they're effective.

SOURCES: John Osborne, M.D., director, cardiology, State of the Heart Cardiology, Dallas; Raymond Townsend, M.D., American Heart Association, volunteer expert, and professor of medicine and director, hypertension program, University of Pennsylvania

You’ve made the decision to monitor your blood pressure at home. Congratulations! You have made a huge step toward taking control of your health and taking good care of your heart. Now the question is, what is the best way to do this? When you should check your blood pressure, how often and what affects the results, are all good questions. Here are some answers.

When Should I Check My Blood Pressure?

Our blood pressure fluctuates during the day, so when you start tracking your blood pressure, you should check it at different times of the day, about 5-6 times. Once you establish a routine of checking your blood pressure and have gained a better understanding of the numbers, you can begin checking it once or twice a day, at the same time each day.

What time of day is your blood pressure the lowest

If it has already been determined that you have high blood pressure, it is important to measure your blood pressure at roughly the same times each day. This will provide consistent readings less affected by other factors, and therefore show how well your medication and dosage are working.Getting into the habit of checking your blood pressure in the morning and again before bed is generally the best practice. For the A.M. reading, don’t take it immediately when you wake up; however, you should measure before breakfast or your morning coffee.

What If I’m Taking Medication? Does This Affect When I Should Check My Blood Pressure?

Yes. If taking high blood pressure medication, your blood pressure measurements should coincide with your doses. The best time to check it is before you take your medication. It is at this point that the level of medication in your body will be at its lowest. This is known as a trough value. Measuring your blood pressure before you take the next dose will demonstrate how well the medication has been working.

What time of day is your blood pressure the lowest

Another important variable to consider is symptoms. If you are experiencing a symptom of high blood pressure, it is a good idea to take a measurement then. Of course, if symptoms are severe, contact your doctor or seek immediate assistance.Common symptoms of high blood pressure include:

  • Intense headaches
  • Pounding in your chest, neck, or ears
  • Irregular heartbeat
  • Fatigue
  • Vision problems
  • Chest Pain
  • Breathing issues

Measuring your blood pressure while experiencing these symptoms can help determine if high blood pressure is the cause. It is also possible that your medication has lowered your blood pressure too much. A blood pressure reading during symptoms can also help determine if an adjustment to your medication is needed, either in dosage or time of day it is taken.

What Else Is Important When Checking My Blood Pressure?

Many factors can influence your blood pressure reading. The following guidelines will help you get the best and most accurate results from your blood pressure monitoring.

Avoid Blood Pressure Spikers

What time of day is your blood pressure the lowest

Certain factors can increase your blood pressure. It is important to understand how these “spikers” affect your BP numbers. To learn their effect, check your BP before and after you experience each of the factors listed below. Once you know their effect, avoid these spikers before your daily checkup routine. This will prevent them from interrupting your baseline measurement and will allow you to see if your standard BP is stable. As you establish your BP routine, use the following guidelines to control spikes in your readings.

  • Caffeine – Hold off on the morning cup of coffee before measuring your blood pressure. No caffeine for half an hour before measuring is best.
  • Tobacco – If you can stop altogether, your heart will thank you. Otherwise, avoid for at least half an hour before you take a measurement.
  • Exercise – Great to do, just wait until after you check your blood pressure. Avoid exercise for thirty minutes prior to blood pressure readings.
  • Medication – For an accurate reading, you should have as little medication in your blood as possible.
  • Food – Wait to eat until after you check your blood pressure.
  • Alcohol – Avoid alcohol consumption for at least half an hour before checking your blood pressure.
  • Cold Temperatures – Your heart will be working hard to keep you warm in an arctic blast. Get to a comfortable temperature before measuring.
  • Full Bladder - A full bladder can cause a rise in blood pressure. So, make a restroom stop before you measure.
What time of day is your blood pressure the lowest

Choose A Good Machine

Myriad choices exist in today’s marketplace for home blood pressure monitoring devices. Not all are equal. Be sure to choose an FDA-approved device. Once you have selected a machine, it not a bad idea to take it in to your doctor’s office. Take your blood pressure reading in front of your physician,  nurse or PA so they can ensure you are using it properly. Have them to take an additional reading on their machine, to compare for accuracy.

What time of day is your blood pressure the lowest

Take the Proper Position for Reliable Blood Pressure ReadingsEnsure you are positioned correctly for accurate blood pressure readings. Put your feet on the floor and straighten your back with arms supported at heart level. Make sure your elbow is at about the same level as your heart.

What time of day is your blood pressure the lowest

Give yourself five minutes to rest quietly before slapping on the cuff. Because blood pressure can fluctuate, it’s a good idea to take at least two readings each time. Always use the same arm, as readings can fluctuate from arm to arm. Track all of the results. To make tracking easy, use an easy-to-use app (iOS, Android).

Why Does My Blood Pressure Vary Throughout The Day?

You may have heard the term circadian rhythm. If so, you know this is not a beat to keep on the dance floor. It is a biological cycle your body follows. As defined by the National Institute of General Medical Sciences, “Circadian rhythms are physical, mental and behavioral changes that follow a roughly 24-hour cycle, responding primarily to light and darkness in an organism's environment.” As your body cycles through this rhythm each day, responding to both internal and external stimuli, your blood pressure is affected.

What time of day is your blood pressure the lowest

The study of these important rhythms, known as chronobiology, was founded by Franz Halberg. His work in this field has helped identify abnormal rhythms in day-night blood pressure readings.Keeping the Beat of Blood PressureFollowing this chronobiological rhythm, your blood pressure is normally higher during the daytime and lower at night, during sleeping hours. Here’s the problem. People with high blood pressure often don’t experience this night time dip. This lack of a lowering of blood pressure at night is referred to as non-dipping.What’s the big deal? Heart attack and stroke have been found to be associated with non-dipping. Your blood pressure stays elevated, and your body is not in the relaxed state it should be during rest.

How Does My Circadian Rhythm Affect My Blood Pressure Medication?

Michael Smolensky, adjunct professor of biomedical engineering at the University of Texas, Ausin, reports, “"The body doesn't respond to medications in the same way at different times of the day. Some drugs are not as effective or as well tolerated if they're taken at the wrong biological time. It's not that they're not effective at all, but they're certainly much less effective."Studies on chronotherapy (medication scheduling) have found that taking high blood pressure medications before bedtime help with the non-dipping issue. This reduces your risk of heart attack and stroke by normalizing your daily blood pressure rhythm. Specifically, it has been reported that drugs called ACE inhibitors and ARBs are the most effective when taken at bedtime.

What time of day should blood pressure be taken?

At the beginning, measure your blood pressure at least twice daily. Take it first in the morning before eating or taking any medications. Take it again in the evening. Each time you measure, take two or three readings to make sure your results are the same.

How long after you wake up should you take your blood pressure?

Your blood pressure should be checked in the morning, about an hour after you wake up, and in the evening, about an hour before you go to sleep, using the same arm each time. Taking 3 consecutive measurements (about 1 minute apart) will provide a more accurate understanding of your "true" blood pressure.