What is Normal Blood Pressure?
Written by Eli Ben-YehudaOn July 2, 2019
Blood pressure falls into five general categories, ranging from normal blood pressure to hypertensive crisis (This is very dangerous).
The level of your blood pressure will determine the course of treatment your physician may require. To get an accurate blood pressure measurement, your doctor should evaluate your readings based on the average of two or more blood pressure readings at three or more office visits.
What’s a Normal Blood Pressure?
An optimal normal blood pressure level is reading under 120/80 mmHg.
120 represents the ‘top’ number, known as systolic blood pressure. Systolic: The blood pressure when the heart is contracting. It is specifically the maximum arterial pressure during contraction of the left ventricle of the heart. The time at which ventricular contraction occurs is called systole.
80 represents the bottom number, known as the diastolic blood pressure. Diastolic: Referring to the time when the heart is in a period of relaxation and dilatation (expansion). The diastolic pressure is specifically the minimum arterial pressure during relaxation and dilatation of the ventricles of the heart when the ventricles fill with blood.
For many years, readings over 120/80 mmHg and up to 139/89 mmHg were classified as ‘pre-hypertension,’ within the normal to high range. However, the American Heart Association and the American College of Cardiology have recently changed the blood pressure guidelines.
Now, anything between 120-129 systolic pressure with diastolic pressure under 80, is considered ‘pre-hypertension.’ This is when your doctor will recommend you get proactive and make diet and lifestyle changes because, during this early time, you can greatly reduce your risk of cardiovascular problems.
Blood pressure over 130/80 mmHg is now considered to be high.
A hypertensive crisis is blood pressure above 180/120 mmHg. If you experience blood pressure this high it is a medical emergency, so do not delay in visiting the hospital or calling 911.
How to check blood pressure?
When taking blood pressure reading, you should follow these simple rules:
- Make sure your feet are flat on the floor, and legs are uncrossed.
- Ensure your arm and back are properly supported.
- If you need to use the restroom go so you will feel comfortable
- Ensure your arm is bare, and the blood pressure cuff is on the skin, not over any clothing.
- Make sure you do not talk and that you have at least three minutes of quiet time prior to the measurement.
According to research, your blood pressure can elevate between 2-40mmHg by not following the simple guidelines for checking blood pressure. This can result in you being prescribed medication that you did not need.
Did you know?
- When you have a full bladder – your BP can appear higher by 10-15mmHg
- When you have an unsupported back or feet – your BP can appear higher by 5-10mmHg
- When you have crossed legs – your BP can appear higher by 2-8mmHg
- When you have the cuff over clothing – your BP can appear higher by 10-40mmHg
- When you have an unsupported arm – your BP can appear higher by 10mmHg
- When you are talking during reading – your BP can appear higher by 10-15mmHg
Now can you see why it is so important? Please, when you visit your doctor ensure they follow these guidelines while you are getting your blood pressure checked. I have seen medical technicians checking a patients blood pressure when the patient was laughing.
Blood Pressure Chart
The blood pressure chart used to look like this:
Under the new blood pressure guidelines, the blood pressure chart now looks like this:
NOTE: Under these new guidelines, normal blood pressure has not changed, it is still below 120/80 mmHg. Only the higher ranges have changed to provide earlier intervention, with the goal of reducing the incidence of heart disease.
False high blood pressure reading
Elevated blood pressure is difficult to determine from one single reading. For instance, many people get what’s called ‘white coat hypertension.’ This is anxiety produced by the thought of visiting the doctor’s office.
Sudden or increased anxiety can temporarily increase blood pressure levels, which can give an inaccurate reading. Therefore, your physician may recommend you have regular blood pressure checks or use a home blood pressure monitor to record several readings.
How to take blood pressure reading at home
To help ensure accurate blood pressure monitoring at home:
- Check your device’s accuracy. Before using a monitor for the first time, have your doctor check its accuracy against the office model. Also, have your doctor watch you use the device to see if you’re doing it properly. If you drop the device or damage it, have it checked before using it again.
- Measure your blood pressure twice daily. The first measurement should be in the morning before eating or taking any medications, and the second in the evening. Each time you measure, take two or three readings to make sure your results are accurate. Your doctor might recommend taking your blood pressure at the same times each day.
- Don’t measure your blood pressure right after you wake up. You can prepare for the day, but don’t eat breakfast or take medications before measuring your blood pressure. If you exercise after waking, take your blood pressure before exercising.
- Avoid food, caffeine, tobacco, and alcohol for 30 minutes before taking a measurement. Also, go to the toilet first. A full bladder can increase blood pressure slightly.
- Sit quietly before and during monitoring. When you’re ready to take your blood pressure, sit for five minutes in a comfortable position with your legs and ankles uncrossed and your back supported against a chair. Try to be calm and not think about stressful things. Don’t talk while taking your blood pressure.
- Make sure your arm is positioned properly. Always use the same arm when taking your blood pressure. Rest your arm, raised to the level of your heart, on a table, desk or chair arm. You might need to place a pillow or cushion under your arm to elevate it high enough.
- Place the cuff on bare skin, not over clothing. Rolling up a sleeve until it tightens around your arm can result in an inaccurate reading, so you may need to slip your arm out of the sleeve.
- Take a repeat reading. Wait for one to three minutes after the first reading, and then take another to check accuracy. If your monitor doesn’t automatically log blood pressure readings or heart rates, write them down.
Blood pressure varies throughout the day, and readings are often a little higher in the morning. Also, your blood pressure might be slightly lower at home than in a medical office, typically by about five points.
Contact your doctor if you have any unusual or persistent increases in your blood pressure. Ask your doctor what reading should prompt an immediate call to the medical office.
Blood pressure by age
Average readings tend to be lower at a younger age and increase with age. During late adolescence years (around 17-19 yrs old) doctor typically begins to follow the standard adult guidelines for high blood pressure.
As we age, our bodies become more susceptible and at higher risk of developing high blood pressure.
In normal blood pressure for elderly & adults over 50, increased systolic blood pressure is a major risk factor for heart disease. Systolic blood pressure tends to increase steadily over time due to stiff arteries, a build-up of plaque, and a higher rate of cardiac and vascular disease. This means older adults need to be even more vigilant about monitoring their blood pressure.
According to the National Institute on Aging, males are more likely to have high blood pressure before age 55, while normal blood pressure for women tends to see a rise in after menopause. Women are less likely than men to experience complications associated with high blood pressure.
However, regardless of differences in the prevalence and complications of high blood pressure between the sexes, treatment and diagnosis are the same for both men and women.
Normal blood pressure for men and women
Refer to the below chart for Prevalence of hypertension among adults aged 18 and over, by sex and age
Men are at greater risk for cardiovascular and renal disease than are age-matched, premenopausal women. Recent studies using the technique of 24-hour ambulatory blood pressure monitoring have shown that blood pressure is higher in men than in women at similar ages
After menopause, however, blood pressure increases in women to levels even higher than in men. Hormone replacement therapy in most cases does not significantly reduce blood pressure in postmenopausal women, suggesting that the loss of estrogens may not be the only component involved in the higher blood pressure in women after menopause. In contrast, androgens may decrease only slightly, if at all, in postmenopausal women.
Why is normal blood pressure so important?
Maintaining normal blood pressure is essential for heart health. When your blood pressure is high, your heart and arteries can become overloaded.
High blood pressure can accelerate the buildup of plaque on the artery walls (atherosclerosis), clogging blood flow to your heart muscle, putting you at risk of heart attack. It also weakens the walls of arteries in your brain which can cause a stroke.
It can affect arteries to other parts of your body too, such as the eyes, kidneys, and legs. Long-term high blood pressure is known as hypertension and is one of the main risk factors for heart disease.
- Causes for high blood pressure
- Diastolic blood pressure and how to lower it naturally
- How to maintain a healthy blood pressure
- How I shocked my physician
Reviewed by Dr. Cynthia Thaik, M.D.
Dr. Cynthia is a Harvard-trained Los Angeles cardiologist.