Calcium Score Test (Heart Scan): What It Shows, Score Ranges and Who Needs It
Updated: 3 days ago
Written and medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: November 2026 · How we review
Quick Answer: What is a calcium score test?
A calcium score test, or heart scan, is a quick CT scan that measures calcium in the coronary arteries. Calcium is a sign of plaque buildup. A score of 0 is normal, and higher scores mean more disease and a higher risk of heart attack. It helps decide whether you need preventive treatment such as a statin. [1]
What the research says
Higher scores track with higher 10-year risk. In 6,814 adults followed for a median of 11.1 years, 10-year heart attack and stroke event rates were 1.3% to 5.6% with a score of 0 and 13.1% to 25.6% with a score above 300, and each doubling of calcium raised risk by about 14%. (Budoff et al., European Heart Journal, 2018) [2]
A score of zero is the strongest reassurance test. Comparing 13 "negative" risk markers in the same cohort, a calcium score of 0 caused the largest downward shift in estimated heart disease risk (diagnostic likelihood ratio 0.41 for coronary heart disease). (Blaha et al., Circulation, 2016) [3]
Key takeaways
The test is a noncontrast CT scan of the heart that takes about 10 to 15 minutes. [1]
It is most useful for people aged 40 to 70 with borderline heart risk and no symptoms. [1]
Scores range from 0 to over 1,000; 0 is normal and anything above 0 shows some coronary artery disease. [1]
Radiation is about the same as a year of natural background exposure; it isn't done in pregnancy. [1]
Results guide decisions about statins, lifestyle changes and more testing. [1]
What does a calcium score test show?
The scan looks for calcium in your coronary arteries. Calcium there signals a buildup of waxy, fatty plaque that can narrow or block the arteries. This is atherosclerosis, or coronary artery disease, which can lead to a heart attack. [1]
The test can't see every kind of plaque. It misses "soft plaque," so it can't predict heart attack or stroke risk perfectly. It is one more tool your provider uses, alongside your other risk factors. [1]
Calcium score ranges and what they mean
Score | What it means |
0 | Normal. No calcium found, and a very low risk of heart attack in the next 2 to 5 years |
1 to 100 | Mild evidence of coronary artery disease |
101 to 400 | Moderate evidence of coronary artery disease |
Above 400 | Strong evidence of coronary artery disease |
Sources: [1]
A score above 0 is called a positive test. Your provider interprets it along with your family history, lifestyle and medical conditions to estimate your future risk. [1]
Who should get a calcium score test?
The test helps most when your heart risk is neither clearly high nor clearly low. It may help if you are 40 to 70 years old, have no symptoms and have increased risk, such as: [1]
A family history of heart disease
Current or past tobacco use
High cholesterol, diabetes or high blood pressure
Overweight (BMI over 25) or obesity (BMI over 30)
An inactive lifestyle
Other, nontraditional risk factors
If you are younger than 40 and high cholesterol runs in your family (familial hypercholesterolemia), you might also consider the test. [1]
Who shouldn't get a calcium score test?
Pregnant people shouldn't have the test, because a CT scan could harm a fetus. The test may also not be helpful if you: [1]
Have no risk factors for heart disease
Are already at high risk
Have been diagnosed with coronary artery disease or have symptoms of it
Have been treated for coronary artery disease
Want to know if heart disease treatment is working
How often should you have the test?
Studies suggest a repeat test every three to five years may help, but only if your first score was normal and you want to know whether your risk is still low. Repeating it isn't useful after an abnormal result. [1]
How do you prepare?
Before your test: [1]
Tell your provider about allergies, medicines and whether you are or could be pregnant
Avoid food, drinks, caffeine and tobacco for four hours
Remove metal such as jewelry and glasses, and change into a gown
What happens during the test?
You lie on your back on a table that slides into a doughnut-shaped CT scanner. A provider cleans three small areas of your chest and places electrode patches connected to an EKG monitor, which times the pictures to your heartbeat. You may need to hold your breath for 10 to 20 seconds while the scanner takes images, and a computer program then measures any calcium in your coronary arteries. [1]
The scan itself takes a few minutes and the whole visit about 10 to 15 minutes. No contrast dye is injected, and you can eat and return to normal activities right after. [1]
Are there risks?
Because no dye is used, there are no dye-related side effects. There is a very small cancer risk from radiation, especially with several CT scans and in people under 40. The dose is about the same as you'd get naturally in a year. [1]
Results and next steps
Some hospitals give results the same day; others take two days or more. A radiologist reviews the scan and sends results to your provider. Contact your provider if you haven't heard within a week. [1]
If your score is abnormal, you may be referred to a cardiologist, who may recommend: [1]
A statin to manage cholesterol
More exercise and changes to your diet
More tests
More follow-up visits
A calcium score test doesn't show exactly which arteries are blocked. Other tests check how well blood flows; this one shows calcium in arteries with plaque. [1]
Conclusion
A calcium score test is a fast, noninvasive way to add real information to a heart risk estimate, especially when the decision about preventive treatment isn't clear-cut. A score of 0 is reassuring, and a higher score is a prompt to act on cholesterol, lifestyle and follow-up. [1]
Ask your provider whether your risk level makes the test worthwhile. If you have chest pain or other heart symptoms, don't wait for a screening test; seek medical care.
Keep learning: Read our guide to coronary artery disease or learn about familial hypercholesterolemia. For more background, see the cardiac CT for calcium scoring guide from RadiologyInfo.
FAQ
What is a calcium score test?
It is a quick CT scan that measures calcium in your coronary arteries, a sign of plaque buildup. [1]
What is a normal calcium score?
A normal score is 0, which means no calcium was found in your coronary arteries. [1]
What does a calcium score of 100 or 400 mean?
A score up to 100 shows mild coronary artery disease, 101 to 400 moderate and above 400 strong evidence of disease. [1]
Who should get a calcium score test?
It helps most for people aged 40 to 70 without symptoms whose heart risk is borderline. [1]
How do I prepare for a calcium score test?
Avoid food, drinks, caffeine and tobacco for four hours, and tell your provider if you might be pregnant. [1]
How long does a calcium score test take?
The scan takes a few minutes and the whole visit about 10 to 15 minutes. [1]
Is a calcium score test safe?
It uses no dye and a radiation dose similar to a year of natural exposure, but it isn't recommended in pregnancy. [1]
Does a calcium score test show blocked arteries?
Not exactly. It shows calcium in arteries with plaque, while other tests show how well blood flows. [1]
How often should I repeat a calcium score test?
Every three to five years may help, but only if your earlier score was normal. [1]
What happens if my calcium score is high?
Your provider may recommend a statin, diet and exercise changes, more tests or a cardiologist visit. [1]
Related Reading
Coronary Artery Disease: Symptoms, Causes, Diagnosis, Treatment and Prevention — What You Need to Know explains the condition a calcium score test looks for.
Arteriosclerosis & Atherosclerosis: Symptoms, Causes, Diagnosis & Treatment — Complete Guide covers the plaque buildup that calcium scoring detects.
Familial Hypercholesterolemia: The Inherited Cholesterol Condition Most People Never Know They Have explains the inherited cholesterol condition that can justify a scan before age 40.
Understanding Hyperlipidemia: Managing High Cholesterol for Heart Health covers high cholesterol, a key reason doctors order this test.
References
Cleveland Clinic. Calcium Score Test. Cleveland Clinic. Last updated May 3, 2023. https://my.clevelandclinic.org/health/diagnostics/16824-calcium-score-screening-heart-scan
Budoff MJ, Young R, Burke G, et al. Ten-year association of coronary artery calcium with atherosclerotic cardiovascular disease (ASCVD) events: the multi-ethnic study of atherosclerosis (MESA). Eur Heart J. 2018;39(25):2401-2408. PMID 29688297. https://doi.org/10.1093/eurheartj/ehy217
Blaha MJ, Cainzos-Achirica M, Greenland P, et al. Role of Coronary Artery Calcium Score of Zero and Other Negative Risk Markers for Cardiovascular Disease: The Multi-Ethnic Study of Atherosclerosis (MESA). Circulation. 2016;133(9):849-858. PMID 26801055. https://doi.org/10.1161/CIRCULATIONAHA.115.018524
Medical disclaimer
This article is for general education only and does not replace advice from a qualified healthcare professional. Talk to your doctor about your own diagnosis and treatment, and seek emergency care right away for severe or sudden symptoms.
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