Blood pressure is one of the core vital signs, and our best indicator of cardiovascular health. Bad blood pressure can be an early warning sign of potentially severe heart problems, or even kidney or thyroid disease and other conditions.
The average person has their blood pressure measured at every visit to a doctor or clinic, but what does it mean? What are good blood pressure readings anyway?
What is Blood Pressure?
Blood pressure is measured by testing and recording two values:
The Systolic Pressure
This is the maximum amount of pressure in your veins when they are filled with blood as your heart beats.
The Diastolic Pressure
This is the minimum amount of pressure when your veins relax between beats.
Blood pressure is always recorded as those two values, in millimeters of mercury, so it’s written as (for example) 120/80 mmHg.
What is Good Blood Pressure?
Naturally, there is no single value that is a “normal” blood pressure. Blood pressure varies by age, sex, fitness level, time of day, mood, diet, family history, and many other factors. One reason to take and record blood pressure frequently is to minimize small, daily variations and get a better picture of the whole health of the patient.
In 2017, the American Heart Association updated their guidelines for blood pressure categories. The new reference chart for good blood pressure for adults is as follows:
|Category||Systolic Pressure||Diastolic Pressure|
|Low||below 90||or||below 60|
|High Blood Pressure: Stage 1 Hypertension||130-139||or||80-89|
|High Blood Pressure: Stage 2 Hypertension||over 140||or||over 90|
|Hypertensive Crisis||over 180||and/or||over 120|
Blood pressure can also vary by age and sex, so here are the guidelines for the ideal blood pressure at every age:
|Infants below 2||80/34 – 120/75||83/38 – 117/76|
|Children 3-9||100/59 – 109/72||100/61 – 110/72|
|Children 10-13||111/73 – 117/75||112/73 – 117/76|
|Children 14-18||120/75 – 120/80||119/77 – 120/80|
|Adults over 60||134/84||135/88|
Recent studies suggest that, before menopause, women have on average lower blood pressure than men, although it can equal or exceed male blood pressure after menopause..
What About “age+100”?
In the 1960s and 70s, most physicians estimated that a systolic blood pressure of “100+your age” was a normal reading. It was a convenient rule of thumb, so it was easy to adopt and lingered for a long time.
However, if you carry that to its natural conclusion, it would lead to 60-year-old adults with systolic blood pressure of over 160 not receiving treatment for hypertension, which we now understand is a very unhealthy measure. Instead, the current goal is to keep everyone at a healthy adult blood pressure regardless of their age.
Why Do the Guidelines Keep Changing?
Some people have noticed that recent decades have seen a trend with the American Heart Association lowering their values for “normal” or healthy systolic blood pressure. This lowering of systolic pressure is associated with reduced risk of cardiovascular events, and supported by medical research, and yet some question whether it is necessary to treat values below 130/80 mmHg as pre-hypertensive and advise drug therapies.
In fact, current guidelines from the European Society of Cardiology differ from the 2017 American Heart Association guidelines, when previous decades had seen the two organizations in widespread agreement. Current ESC guidelines call for drug treatments in patients with a blood pressure over 140/90 until age 79, then 160/90 in patients over the age of 80, with a target of maintaining blood pressure below 140 at any age.
European cardiologists disagree with the AHA guidelines that do not adjust based on the patient’s age. However, it is also worth noting that European clinicians have a different array of antihypertensives to use to treat patients, which can also influence when and how drug therapies are used and recommended.
As you can see, there can be some disagreement about what “good” blood pressure readings are, particularly when the numbers get higher.
And, given the urgent health risks associated with high blood pressure, and the predominance of people with high systolic values, we tend to overlook the health risks associated with blood pressure that is too low. But everyone agrees that 120/80 is the ideal blood pressure for a healthy adult.