Accurate blood pressure measurements, including blood pressure differences when lying down versus standing up and sitting can be very helpful when healthcare providers are trying to monitor the condition. However, it’s important to understand the impact that each position has on blood pressure levels.
There are three common positions that healthcare workers use when taking someone’s blood pressure. Taking blood pressure lying down is the obvious method used when a patient is hospitalized, but in a doctor’s office a patient is usually sitting in a chair. Some nurses also measure blood pressure while a person is standing.
Records show that diastolic pressure is about 55mm/Hg lower when taking blood pressure lying down vs. sitting. Systolic pressure is approximately 88 mm/Hg in the lying down position versus the sitting position, but only when the person taking the measurement positions the patient’s arm so that it is at the same level as the right atrium of the heart.
People should also be conscious of the fact that blood pressure readings are different if you are in a sitting position with your legs crossed. It actually increases systolic pressure by as much as 8mm/Hg.
Orthostatic hypotension is a type of low blood pressure that can occur when you stand up after lying or sitting down. It often causes dizziness and even fainting. Some doctors refer to it as postural hypotension. Older people are more at risk for postural hypotension, and so are people with heart conditions.
Blood pressure lying down (supine position) vs. standing
Without blood pressure, our body would not receive the oxygen and nutrients it needs to function properly. The heart has two motions – contracting and relaxing, so blood pressure is, therefore, recorded as two numbers over each other. Systolic is the actual beat of the heart and diastolic is when the heart relaxes. Systolic pressure is listed over diastolic, such as 120 over 80, which is normal blood pressure.
All sorts of conditions can have an impact on your blood pressure reading. Disease, stress, weight, and even posture can impact your blood pressure level. Blood pressure lying down verses standing has the same variations as lying down vs. sitting. Moving from a standing to a supine (lying down) position could result in different readings.
Blood pressure lying down vs. sitting
Many wonder why positioning makes such a difference in blood pressure readings. Let’s take lying down vs. sitting as an example. Our heart is a pump, and it takes less work to pump blood to our brain when we are lying down. This is because our head is about the same level as our heart. However, when we are up, our head is a lot higher than our heart. This means the heart has to pump much harder to get blood to our brain, so as a result, blood pressure is higher.
In most cases, blood pressure is taken while a person is sitting down with the arm dropping onto a table. While sometimes the middle point of the upper arm might, in fact, be parallel and in line with the position of the heart, the rest of the arm is not, so it should not be surprising that the measurement taking while laying down might be a little lower, since there is less gravity to counter.
Orthostatic hypotension, blood pressure when you stand up from sitting or lying down
If you stand up from a sitting or lying down position and experience orthostatic hypotension, it is likely that your systolic blood pressure has decreased at least 20 mm/HG or your diastolic blood pressure has decreased at least 10 mm/HG within three minutes of standing. It is not uncommon to feel a slight drop in blood pressure and, perhaps, experience a slight lightheaded feeling, but when the feeling lasts for a few minutes and when it happens on a regular basis, you should see a doctor. Orthostatic hypotension or postural hypotension can be a sign of a serious health problem.
Related: Surprising causes of high blood pressure, simple strategies to manage hypertension
Blood pressure differences between arms
Finding blood pressure differences between arms can be a sign of atherosclerosis, which is basically plaque buildup in arteries. Finding a difference in pressure between sides of the body tells doctors that they need to investigate further to see if atherosclerosis is in the main blood vessel leaving the heart or in other parts of the body.
One study published in the medical journal The Lancet stated that a blood pressure difference of 10 to 15 points between arms increases the risk of dying from heart disease or a stroke.
A small difference in blood pressure between arms is nothing to panic about. A large difference could signal health problems that include not only plaque buildup, but also kidney disease, diabetes, and heart defects.
Related: Fluctuating blood pressure: Causes and treatments
Blood pressure measuring tips
Consider that when your blood pressure is being measured, your arm should be at the level of your heart. If the arm is hanging down whether you are sitting or standing, the arm should be extended out. If you are lying down, the arm should be along your side, leveled with your body.
Aside from being aware of your arm position, here are some other tips to keep in mind when having your blood pressure measured:
- Rest for about five minutes before the reading is taken.
- Try not to eat or exercise for 30 minutes before a screening.
- Have your reading in the morning, since your body’s rhythms can cause blood pressure to rise in the afternoon and evening.
- Have your pressure taken from all three positions: sitting, standing, and lying down.
- Have your blood pressure taken three times in one session with one minute of rest between each test.
Don’t get caught up in comparing your blood pressure to others. Instead, know that there is a healthy blood pressure level for each sex and specific age. Here you can find an age and gender chart you can check to see what your healthy range is.
Monitoring your blood pressure on a regular basis can give you the most accurate picture of what is happening with your blood pressure. There are some common factors that can impact your pressure readings. Many are related to lifestyle and include smoking, diet, and physical activity level. Family history can also play a role, as can stress.
Blood pressure issues must be taken seriously, as both high blood pressure and low blood pressure can cause damage to the heart. Monitoring blood pressure is not a difficult or painful task. It’s a small step to take to save your health and possibly your life.
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