Blood pressure is essential for healthy blood circulation. Blood must move from our heart to all parts of the body, and the pressure, or resistance, is measured. Blood pressure that is too high means that there is too much resistance and is typically what health professionals refer to as high blood pressure, or hypertension. There is not a normal or average "range" for blood pressure, meaning you don't need to stay between two numbers. A normal blood pressure for any age, male or female, is a reading less than 120/80. The Centers for Disease Control and Prevention estimate that 1 in 3 Americans, or 29 percent have blood pressure that is too high.
Normal Blood Pressure in Babies and Children
A "normal" blood pressure changes throughout childhood — it's lowest in infants and gradually increases throughout childhood. For example, an average one year old would have a blood pressure of 85/37, and that same child at age 10 would have a blood pressure of 102/61, according to data from the National Institutes of Health.
A child usually has their blood pressure taken at their yearly check-up to document changes over time. Determining normal blood pressure in children is a bit complicated, and it depends on the child's size and age. One rule of thumb doctors use is this: a child is considered to have "prehypertension" if she has a blood pressure greater than 90 percent of children of similar age and size, and to have "hypertension" if she has a blood pressure greater than 95 percent, per the guidance from the U.S. Department of Health and Human Services.
Normal Blood Pressure in Adolescents and Adults
It may seem surprising, given that blood pressure naturally increases with age, but a normal blood pressure is considered the same for all adolescents and adults, whether someone is 20, 60, or 70 years old - below 120/80.
The first, or top number of the blood pressure reading, the systolic blood pressure, reflects the pressure in the blood vessels when the heart is contracting and exerting maximum pressure. The second, or bottom number, the diastolic blood pressure, reflects the pressure in the blood vessels when the heart is at rest, between contractions. If either one of those two numbers is too high, the blood pressure is not considered normal.
High Blood Pressure
Adults are considered to have prehypertension if their systolic blood pressure reading is consistently above 120 but below 140, or if their diastolic blood pressure is above 80 or below 90. People with prehypertension are likely to progress to having hypertension unless they take some measures to lower their blood pressure.
If you have a blood pressure greater than 140/90, you are considered to have hypertension. Your doctor might recommend certain lifestyle habits that can help lower your blood pressure, such as maintaining a healthy weight, exercising regularly, quitting smoking, and limiting your intake of alcohol and salt. Depending on how high your blood pressure is and what other health problems you have, your doctor might also recommend blood pressure medication.
Low Blood Pressure
Although it's a less common problem than high blood pressure, your blood pressure might become lower than normal at any age. Some people have naturally low blood pressure without experiencing any symptoms, but for others, a low systolic blood pressure — typically lower than 90 — can result in symptoms such as dizziness, lightheadedness, or fainting, according to the National Heart Lung and Blood Institute.
The American Heart Association indicates low blood pressure may be caused by another problem, such as dehydration, sudden blood loss, medications, pregnancy, or nutritional deficiencies, and your doctor will recommend treatment depending on the cause.
What Can Make a Normal Blood Pressure Abnormal?
At any age, certain factors can lead to a dangerous level of blood pressure, even in people with a normally healthy blood pressure. Caffeine and tobacco are both stimulants, which can lead to high blood pressure readings. In addition, the Mayo Clinic indicates that tobacco damages the lining of your arteries, which can cause them to be more restrictive, causing high blood pressure.
Being woken up suddenly or exercising right before a reading can cause it to be high. Stress can also elevate a normal reading. Some people experience stress whenever they're in a doctor's office, leading to higher-than-normal readings — so-called white-coat hypertension.
Nutrition can also have an impact on blood pressure. A diet high in sodium has been shown to increase blood pressure. Often times, decreasing the amount of sodium in the diet is helpful in bringing down blood pressure numbers.
- NIH MedlinePlus: Blood Pressure Numbers: What They Mean
- MedlinePlus: Blood Pressure Measurement
- NIH National Heart, Lung and Blood Institute: How Is High Blood Pressure Diagnosed?
- NIH National Institute on Aging: High Blood Pressure
- NIH National Heart, Lung and Blood Institute: Who Is at Risk for High Blood Pressure?
- National Institutes of Health: Chart for Blood Pressure Levels for Boys by Age and Height Percentile
- U.S. Department of Health and Human Services:A Pocket Guide to Blood Pressure Measurement in Children
- Mayo Clinic: High Blood Pressure
- CDC: High Blood Pressure FAQs
- LIVESTRONG: High Blood Pressure
- LIVESTRONG: Nutrition to Reverse High Blood Pressure
- NIH - National Heart Lung and Blood Institute: Low Blood Pressure
- American Heart Association: Low Blood Pressure
- Normal Blood Pressure Range for Children
- LIVESTRONG: What is a Healthy Blood Pressure for Teens?
- LIVESTRONG: What are the Dangers of Low Blood Pressure?