What your numbers actually mean for your heart
A visual guide and calculator built on PREVENT, the American Heart Association equations that the 2025 blood pressure and 2026 cholesterol guidelines now use. Enter whatever you know. The estimate gets sharper with every number you add.
TL;DR
This is for education and conversation with your clinician. It isn't a diagnosis. Chest pain, trouble breathing, a sudden severe headache, or weakness, numbness or trouble speaking means calling 911.
Your 10-year heart risk
For adults aged 30–79 who have never had a heart attack, stroke, or heart procedure. Anything you leave blank is filled in with typical values for someone your age, and the result shows how much that adds to the uncertainty.
The basicsNo tests needed
Blood pressureHome or office readings
CholesterolFrom a lipid panel blood test
Kidney & blood sugarFrom routine blood and urine tests
Family & extra factors"Risk enhancers" and calcium score
Just saw a scary number on the cuff?
Take a breath. Here's how to read it, why it moves around so much, and when a number really does need action today.
Where a reading falls
Categories from the 2025 AHA/ACC guideline. If the top and bottom numbers land in different categories, the higher one counts. A diagnosis is based on the average of readings over days to weeks.
Why readings jump around
BP rises and falls all day: it dips during sleep, climbs in the morning, and spikes with stress, caffeine, a full bladder, talking, or chasing toddlers to bed. Each dot is a reading someone might take. Tap the button to take one at a random moment.
About the bottom number (diastolic)
The top number (systolic) is the pressure when your heart squeezes. The bottom number (diastolic) is the pressure between beats, while your heart refills and its own arteries fill with blood.
In people under about 50, the bottom number often creeps up first, while the top number is fine. Large studies have found that a slightly raised diastolic on its own (80–89 with a normal top number) adds little measurable heart risk. A diastolic that stays at 90 or above is worth treating seriously over time. Over a lifetime, the top number predicts heart attack and stroke more strongly.
So a 127/90 reading at 40 is a reason to measure properly and look at the average, plus a good reason to see your doctor (which is exactly the right move). It isn't a sign of an imminent heart attack.
How to take an accurate home reading
- No caffeine, exercise, or smoking for 30 min. Empty your bladder.
- Sit quietly for 5 minutes, back supported, feet flat, legs uncrossed.
- Cuff on a bare upper arm, arm resting at heart level. Use the right cuff size.
- Don't talk or scroll. Take 2 readings 1 minute apart.
- Do this morning and evening for about 7 days, then average them (skip day 1).
A cuff that's too small, an arm hanging down, or talking can each add 5–10+ mmHg.
When it IS urgent
Call 911 if any reading comes with chest pain or pressure, shortness of breath, back pain, numbness or weakness, a drooping face, trouble speaking, vision changes, confusion, or a sudden severe headache, whatever the number.
Above 180/120 with no symptoms: sit quietly for 5 minutes and recheck. If it's still that high, contact your clinician the same day.
Anything below that, with no symptoms: not an emergency. Track it, average it, and bring it to a scheduled visit.
Before you re-measure: one minute of slow breathing
Anxiety about a reading raises the next one. Slow breathing at about 6 breaths a minute calms the nervous system and helps you get a truer number.
What's actually happening inside
PREVENT predicts three things: heart attack and stroke (together called ASCVD) and heart failure. Tap the parts of the heart to see how each one comes about.
The heart feeds itself first
The heart muscle gets its own blood supply through the coronary arteries (gold). They're only about as wide as a drinking straw. When plaque narrows or blocks one of them, part of the heart muscle loses oxygen. That's a heart attack.
The same process in arteries to the brain causes most strokes. Long-term strain on the heart muscle, from pressure, diabetes, weight or kidney disease, can lead to heart failure.
How plaque builds, over decades
Drag the slider through the stages of atherosclerosis. It usually starts in your 20s and builds slowly, which is why prevention works.
The three outcomes PREVENT predicts
Stroke: a clot or bleed cuts off blood to part of the brain. High blood pressure is the biggest modifiable cause.
Heart attack: a plaque in a coronary artery cracks and a clot forms on it. Cholesterol and smoking drive this most.
Heart failure: the heart muscle gets stiff or weak and can't keep up. Linked to blood pressure, diabetes, weight, and the kidneys (gold).
Each number, and where yours falls
Each factor damages arteries in a different way. Once you've entered your numbers above, a marker shows where you sit on each range.
From Framingham to PREVENT
75 years of risk prediction
The 2026 "CPR" approach
10-year ASCVD risk categories
PREVENT estimates run roughly 40–50% lower than the old PCE, so the cut-offs were lowered to match. A "5%" today means about what "7.5–10%" meant on the old calculator.
Coronary calcium (CAC) score
A quick, low-radiation CT scan that measures calcified plaque directly. It's the strongest "tie-breaker" when the decision is uncertain.
Why not just use Framingham?
Framingham was built mostly from white residents of one town starting in 1948, when heart disease was far more common. Applied to people today, it tends to overestimate. PREVENT was built and tested in millions of diverse, contemporary Americans. It also adds kidney function, which turns out to matter a lot. Canada's CCS still uses a modified Framingham score, so this tool shows it as a comparison.
Limits & fine print
This tool is for education and shared decision-making. It doesn't diagnose and isn't medical advice. PREVENT is validated for adults 30–79 without known cardiovascular disease. Inputs outside its validated ranges (SBP 90–180, total cholesterol 130–320, HDL 20–100, BMI 18.5–39.9, eGFR 15–140) are capped at the edge of the range, and the tool flags it when that happens.
When you leave something blank, the tool samples plausible values from approximate distributions for US adults of your age and sex, then reports the middle 80% of the resulting risks as the "likely range." These distributions are approximations. Real people aren't averages.
The "what if" panel uses average effects from large trial meta-analyses: about 22% lower relative risk per 1 mmol/L (about 39 mg/dL) of LDL lowering, and about 20% per 10 mmHg of systolic BP lowering. Individual benefit varies.
PREVENT implementation: the base, UACR, HbA1c and full (SDI-missing) models follow Khan SS et al., Circulation 2024, with coefficients cross-checked against the preventr R package test cases (exact match to 3 decimals). Framingham: D'Agostino RB et al., Circulation 2008 general CVD (lipid) model, with risk doubled for premature family history per the CCS-modified FRS. Heart age uses the D'Agostino reference profile (TC 180, HDL 45, SBP 125 untreated, nonsmoker, no diabetes). eGFR from creatinine: CKD-EPI 2021 (race-free).
Sources
- Khan SS, et al. Development and validation of the AHA PREVENT equations. Circulation 2024;149:430–449.
- 2026 ACC/AHA/multisociety Guideline on the Management of Dyslipidemia. Circulation (2026).
- 2025 AHA/ACC Guideline for the Prevention, Detection, Evaluation and Management of High Blood Pressure in Adults. Circulation (2025); top things to know.
- AHA PREVENT online calculator. professional.heart.org.
- Canadian Cardiovascular Society Framingham Risk Score. ccs.ca/frs.
- D'Agostino RB Sr, et al. General cardiovascular risk profile for use in primary care. Circulation 2008;117:743–753.
- McEvoy JW, et al. Isolated diastolic hypertension per the 2017 ACC/AHA definition and cardiovascular outcomes. JAMA 2020;323:329–338.
- Flint AC, et al. Effect of systolic and diastolic BP on cardiovascular outcomes. N Engl J Med 2019;381:243–251.
- Cholesterol Treatment Trialists' Collaboration. Lancet 2010;376:1670–81. Ettehad D, et al. BP lowering meta-analysis. Lancet 2016;387:957–67.
- Inker LA, et al. CKD-EPI 2021 creatinine equation. N Engl J Med 2021;385:1737–49.