The three heart numbers most worth knowing are your blood pressure, your cholesterol and your blood sugar. Each can be high for years without any symptoms, and each is measured with a simple test, which is why they sit at the centre of almost every conversation about heart risk.
Knowing the numbers is not the same as knowing what to do about them. That depends on your age, history and the rest of the picture, and it is a decision to make with your physician. But understanding what the numbers mean makes that conversation far more useful.
Blood pressure
Blood pressure is written as two numbers: the systolic pressure, when the heart beats, over the diastolic pressure, between beats. The American Heart Association and American College of Cardiology use these adult categories: [1]
- Normal: below 120 systolic and below 80 diastolic.
- Elevated: 120 to 129 systolic and below 80 diastolic.
- Stage 1 high blood pressure: 130 to 139 systolic or 80 to 89 diastolic.
- Stage 2 high blood pressure: 140 or higher systolic or 90 or higher diastolic.
A single reading says less than people think. Blood pressure varies through the day and can rise in a clinic. The U.S. Preventive Services Task Force recommends screening all adults 18 and older, and confirming a high office reading with measurements taken outside the clinic before treatment begins. [2] A validated home monitor, used the way your clinician shows you, often gives the clearer picture.
A reading above 180 systolic or 120 diastolic needs prompt medical attention. If it comes with chest pain, shortness of breath, back pain, weakness, or changes in vision or speech, call 911. [1]
Cholesterol
A standard cholesterol test, or lipid panel, reports total cholesterol, LDL cholesterol, HDL cholesterol and triglycerides. LDL is the main focus because it contributes to the build-up of plaque in the arteries; HDL helps carry cholesterol away.
The CDC advises that most healthy adults have their cholesterol checked every four to six years, and more often for people with heart disease, diabetes or a family history of high cholesterol. [3] Current guidelines do not treat a cholesterol result in isolation. They combine it with age, blood pressure, diabetes, smoking and other factors to estimate overall risk, and that overall estimate shapes the discussion about whether and how to act.
Family history matters here. Some people inherit very high LDL levels from an early age, and a parent or sibling with early heart disease is worth mentioning at any visit.
Blood sugar
Blood sugar, or glucose, is usually measured with a fasting glucose test or an A1C test, which reflects average blood sugar over roughly the past three months. The CDC uses these ranges: [4]
- A1C: below 5.7% is normal; 5.7% to 6.4% indicates prediabetes; 6.5% or above indicates diabetes.
- Fasting blood sugar: 99 mg/dL or below is normal; 100 to 125 mg/dL indicates prediabetes; 126 mg/dL or above indicates diabetes.
A diagnosis of diabetes is normally confirmed with repeat testing. The USPSTF recommends screening adults aged 35 to 70 who have overweight or obesity, and many people outside that group are tested because of family history or other risk factors. [5] Diabetes raises the risk of heart disease substantially, which is why it belongs among the heart numbers.
Seeing the numbers together
The American Heart Association’s Life’s Essential 8 puts blood pressure, cholesterol and blood sugar alongside diet, physical activity, nicotine exposure, sleep and weight as the measures of cardiovascular health. [6] The point is that no single number tells the story. A slightly raised reading in someone with no other risk factors means something different from the same reading alongside diabetes, smoking or a strong family history.
Making the numbers useful
- Keep your own record: date, result and where the test was done.
- Ask what each number means for you, not just whether it is flagged high or low.
- Ask when it should be checked again, and what would change the plan.
- Bring home blood pressure readings to visits, with the times they were taken.
Numbers tracked over years tell a much clearer story than any single result. That is one of the quiet advantages of a continuing physician relationship: someone who has seen your earlier readings and can tell a real change from ordinary variation.
General information only; not medical advice. In an emergency, call 911.
About the author. Dr. Irfan Siddiqui is a cardiologist providing concierge care to executives and VIPs through Regenerative Health & Wellness, at home and around the world. More about Dr. Siddiqui · Explore membership.