Taking an accurate blood pressure reading is an important part of monitoring your health. Blood pressure can fluctuate throughout the day and be affected by various factors. One question that often comes up is whether you should rest before taking a blood pressure reading to get the most precise result.
What is blood pressure?
Blood pressure is the force exerted by blood pushing against the walls of the arteries as the heart pumps blood. It is always given as two numbers, such as 120/80 mmHg (millimeters of mercury).
- The first number is the systolic pressure. This is the pressure in the arteries as the heart contracts and pumps blood.
- The second number is the diastolic pressure. This is the pressure as the heart relaxes between beats.
Blood pressure is categorized as:
- Normal: Less than 120/80 mmHg
- Elevated: 120-129/Less than 80 mmHg
- Stage 1 hypertension: 130-139/80-89 mmHg
- Stage 2 hypertension: 140/90 mmHg or higher
Why take blood pressure readings?
Monitoring blood pressure is important because high blood pressure, also called hypertension, often shows no signs or symptoms. If left untreated, high blood pressure can damage the heart, blood vessels, kidneys, and other parts of the body.
Regular blood pressure readings can help:
- Detect high blood pressure
- Monitor medications for high blood pressure
- Identify any health complications
Blood pressure can vary widely, even in the same person throughout the day. Doctors usually base their diagnosis on the average of two or more readings taken at different times.
How to take blood pressure
Proper technique is important for an accurate reading:
- Avoid caffeine, smoking, and exercise for 30 minutes before taking your blood pressure.
- Use an approved arm cuff that fits properly on your arm.
- Sit quietly and still in a chair with your back supported for 5 minutes before taking the measurement.
- Sit with legs uncrossed and feet flat on the floor.
- Rest your arm at heart level on a table with the cuff at the same height as your heart.
- Use the same arm each time.
- Take 2-3 readings, 1-2 minutes apart.
- Record the results each time.
Should you rest before taking blood pressure?
Most experts recommend sitting quietly and resting for 5 minutes before taking your blood pressure. This resting period allows your blood pressure to stabilize and not be affected by any recent activity.
Here are some key reasons why resting beforehand leads to a more accurate reading:
- Avoids falsely elevated readings – Exercise, anxiety, stress, smoking, and even breathing can raise blood pressure temporarily. Resting resets this.
- Allows effects of medication to work – For those taking blood pressure medication, resting for 5 minutes allows the medication to start taking effect before measuring.
- Provides a consistent baseline – Resting helps standardize the conditions so readings can be accurately compared over time.
How long to rest before taking blood pressure?
Most guidelines recommend resting quietly for 5 minutes before taking your blood pressure. Sitting still in a chair for this time allows your blood pressure to stabilize.
Some key recommendations on resting time:
- American Heart Association – Sit for 5 minutes before taking blood pressure
- Mayo Clinic – Avoid exercise, caffeine, smoking, and eating for 30 minutes before measuring blood pressure
- AccuSure blood pressure monitors – Rest for 5 minutes before each reading
Resting for only 1-2 minutes may not allow your blood pressure to reach an accurate baseline. While 5 minutes is often recommended, even longer rest periods of 10-15 minutes can further improve accuracy.
Does the time of day matter for blood pressure readings?
Blood pressure fluctuates naturally throughout the 24 hour daily cycle known as the circadian rhythm. It is typically lowest at night during sleep and begins to rise a few hours before waking.
Blood pressure continues to rise and remains elevated in the afternoon. It reaches its peak in the evening. Nighttime blood pressure normally drops again as you sleep.
Due to these fluctuations, the time of day can impact blood pressure readings. Here is how blood pressure typically varies:
- Highest in the evening
- Lower in the morning within 1-2 hours of waking
- Lowest while asleep at night
Doctors often recommend taking blood pressure in the morning. Measurements in the morning tend to be more consistent as blood pressure has stabilized overnight. Morning readings are also closer to the 24 hour average blood pressure.
How does resting affect morning blood pressure?
For morning blood pressure readings, it is also important to rest for 5-10 minutes beforehand. This allows levels to stabilize after the rise that occurs with waking and getting out of bed.
A reading taken immediately after waking can be falsely elevated by up to 15-20 mmHg. However, resting and then taking blood pressure will provide a more accurate baseline morning value.
Tips for resting before taking blood pressure
Here are some tips to help rest and relax before taking your blood pressure measurement:
- Sit in a comfortable chair with back support.
- Put your feet flat on the floor rather than crossed.
- Place your arm at heart level by resting it on a table.
- Close your eyes, breathe deeply, and clear your mind.
- Avoid talking or looking at your phone/watch.
- Take slow, calm breaths for 5 minutes.
- Relax your muscles and try to feel still and quiet.
An accurate reading requires more than just resting. You’ll also want to follow other proper techniques including using the right cuff size and taking measurements multiple times.
Reasons to take blood pressure without resting
In most cases, resting for 5 minutes is recommended for accurate readings. However, there are some situations where taking blood pressure without resting may be preferred:
- White coat syndrome – Anxiety from being in a doctor’s office can artificially raise blood pressure. A reading without resting shows this white coat effect.
- Emergency care – Need to quickly assess blood pressure in urgent medical situation without time to rest.
- Known normal blood pressure – May skip resting if patient has normal BP and is monitoring for treatment effectiveness.
- Symptoms of low blood pressure – Resting could further lower blood pressure and worsen symptoms.
Talk to your doctor
If you are monitoring your blood pressure at home, it’s important to work with your doctor to get accurate results. Be sure to discuss:
- How long you should rest before taking your blood pressure
- What time of day you should measure it
- How often and what time intervals to check blood pressure
- What your target blood pressure range should be
Your doctor can provide guidance on resting, measuring at consistent times, and interpreting your home blood pressure readings.
The bottom line
Resting for 5-10 minutes before taking your blood pressure allows levels to stabilize and provides an accurate baseline reading. This helps avoid falsely elevated results. While resting is ideal in most cases, speak with your doctor about any specific instructions for measuring your individual blood pressure.
Conclusion
In summary, resting for 5-10 minutes before taking a blood pressure reading is recommended by most medical experts. Sitting quietly without talking, moving, or eating/drinking anything allows your blood pressure to reach a stable baseline. This avoids falsely high measurements that can occur after exercise or stress. Taking readings after proper rest provides consistency and accuracy in monitoring blood pressure.