How long should you wait to take a second blood pressure reading?

Here you can find resources for home monitoring, see our simple steps to get an accurate reading and make the most out of home monitoring.

Plus, read more about why home monitoring can be helpful and how to choose a monitor.

The first step to managing your blood pressure is to Know Your Numbers! Watch our video to see how to measure your blood pressure at home and use our tips and resources below to check your own blood pressure at home.

Home blood pressure monitoring resources

Download our Checking your blood pressure at home [PDF 113KB] poster and our Guidelines for home blood pressure testing [PDF 44KB] to print and keep at home as a guide. 

You can also download our 'Measuring your blood pressure at home' leaflet at the end of the page. This A5 booklet provides clear instructions on how to measure blood pressure at home. It covers how to choose an accurate monitor, how to use the machine correctly at home and when to measure.

Before you measure your blood pressure

• Avoid things that can raise your blood pressure in the short term. Don’t measure your blood pressure within half an hour of eating, smoking, drinking caffeinated drinks such as coffee, or exercising. These can all raise your blood pressure temporarily. If you need to use the toilet, go before you measure your blood pressure.
• Wear loose-fitting clothes. Wear a short-sleeved t-shirt or something with sleeves you can push up easily, nothing tight. This is so that you can fit the cuff around your arm.
• Rest for five minutes before you take your reading. Sit down somewhere quiet, ideally at a desk or table. Have your back supported with your arm resting on a firm surface and your feet flat on the floor. Stay in this position while you take your blood pressure.
• Make sure your arm is supported and at the same level as your heart. Position yourself so that your arm is resting on a surface and is at the same height as your heart. Keep your arm and hand relaxed, not tensed.
• Make sure you are relaxed and comfortable. If you are anxious or uncomfortable, your blood pressure will rise temporarily.

How to measure your blood pressure at home using a home monitor

1. Follow the instructions that came with your monitor. Make sure you place the cuff around your arm as described in the instructions.
2. Place the arm cuff just above your elbow. The cuff should be about 2cm above your elbow to make sure it can detect the artery in your arm, just under the skin. 
3. Keep still and quiet while you take your reading. Moving, chewing, talking and laughing can affect your reading. Make sure you don't cross your legs, as this will raise your reading too.
4. Take two or three readings, each about one to two minutes apart. If your first reading is much higher than the next, ignore it and take an extra reading. Once you have two to three readings, you can work out the average. 
5. Keep a record of your measurements. Record all your readings in the memory of your monitor, on your computer or phone or on paper – whichever you prefer. Write them down exactly as they appear on screen. 

Tips for measuring your blood pressure at home

• Measure your blood pressure in both arms when you first start. They will give slightly different readings. From then on, use the arm that gave you the higher reading each time.
• Always use the same arm. If possible, use the arm that your doctor or nurse uses when they measure your blood pressure.
• Take readings at the same time each day. For example, first thing in the morning or last thing at night. Your blood pressure can vary throughout the day and with different activities, so this will mean you’re comparing like with like. It’s good to have a routine – like measuring your blood pressure before breakfast.
• Don’t round your measurements up or down. Record your readings as they’re displayed because it could affect the treatment you’re prescribed.
• Don’t worry if you get an unexpected high reading. A one-off high reading is usually nothing to worry about, rest for five minutes and take the reading again. If it’s still high, measure your blood pressure again another day. If it remains high for long, around two or three weeks, see your doctor or nurse.
• Don’t worry about small changes. It’s normal for there to be small changes in your blood pressure.
• Don’t check your blood pressure too often. Some people find that they become worried or stressed about small changes in their readings if they take them too often. Worrying can also raise your blood pressure in the short term, making your reading higher than it should be.
• Don’t stop taking your medications if your blood pressure falls. Always talk to your doctor before stopping your medications, even if your blood pressure has fallen to a healthy level according to your home monitor.
• Speak to your doctor or nurse if you’re worried. If you have doubts or concerns about your readings or home monitoring, speak to your doctor or nurse, or call out healthcare team on 020 7882 6218. If you think you may be having a stroke or heart attack call 999 immediately. 

How often should you measure your blood pressure?

When and how often you take your readings will depend on your blood pressure. Speak to your doctor or nurse about what’s suitable for you. 

It can be useful to monitor your blood pressure closely to begin with, then less often but at regular intervals.

When you first start using your home monitor

When you first start using a home monitor, measure your blood pressure in the morning and evening, every day for a week.

Take three readings in the morning, one to two minutes apart, and the same again in the evening, and record all the readings. Take an average of the readings, but discard the first one if it’s much higher than the others. To take an average simply add the two readings together and divide by two. Divide by three if you use all three readings.

Ignore the first day’s readings altogether, because they might not be accurate as you’re not familiar with your monitor yet.

At the end of the week you will have a useful picture of what your blood pressure is normally like.

Your doctor might ask you to keep a record like this when they first think you might have high blood pressure and would like to know more before making a diagnosis.

After the first week

Once you have a record of your blood pressure over a week, you can take readings less often – once every one to two weeks perhaps. Your doctor or nurse can talk to you about this, there’s no need to measure it too often.

If your blood pressure has been stable for a long time, you might only need to measure it once every four to six months. Your doctor or nurse will be able to advise you.

There might be times when you want to measure your blood pressure more often. For example, if you are given a new medicine or a higher dose of medicine, to see if the change is having an effect. It’s also helpful to record your numbers for four to seven days before a clinic visit so you can show your doctor.

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.

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.

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

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.

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.

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.

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.

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.

THE GIST

• Check your blood pressure 2x per day, morning and evening.
• If taking medication, align blood pressure readings with doses.
• Be aware of HBP symptoms, and take readings when they occur.
• Get the best readings by avoiding BP spikers, using a good machine, and testing properly.
• Realize your biological rhythms vary your blood pressure throughout the day.
• Apply chronobiology to decide when to take blood pressure medications.
• Use an easy-to-use app (iOS, Android) to track your daily blood pressure readings.