Your Calcium Score, Explained: What the Number Means for Your Heart

Understanding your coronary artery calcium (CAC) score can feel daunting, but it's simply a measure of calcium deposits in the walls of your coronary arteries. These deposits are a sign of atherosclerosis (plaque buildup) and can help predict your risk of heart disease. Here's what you need to know.

What Is a Coronary Artery Calcium Score?

• A CAC score is obtained via a non-contrast CT scan of the heart.
• It quantifies calcified plaque in the coronary arteries.
• The result is a numerical score: the higher the score, the more calcified plaque you have.

Why It Matters

• Plaque narrows arteries, raising your risk of heart attack and stroke.
• Traditional risk factors (blood pressure, cholesterol, smoking) don't always tell the whole story.
• A CAC score adds individualized information about your actual artery health.

How the Test Works

1. Preparation
   • No special diet or contrast dye is needed.
   • Wear comfortable, metal-free clothing.

2. During the Scan
   • You lie on a table that slides into a CT scanner.
   • The scanner takes images of your heart in a few seconds.
   • There's no pain, and radiation exposure is low.

3. Scoring
   • Software highlights and measures calcium "spots."
   • Each spot is weighted by density and area.
   • Scores are summed for a total CAC score.

Reading Your CAC Score

CAC scores are grouped into risk categories. Keep in mind that age, sex and ethnicity influence what's "normal" for you.

• 0
  – No detectable calcium.
  – Very low risk of heart attack over the next 5–10 years.

• 1–99
  – Mild evidence of plaque.
  – Increased risk, especially if you're over age 50.

• 100–299
  – Moderate plaque burden.
  – Consider more aggressive prevention (statins, lifestyle changes).

• ≥300
  – Extensive plaque.
  – High risk of cardiac events; needs close follow-up.

You can also compare your score to age- and sex-matched percentiles (e.g., 75th percentile means your score is higher than 75% of peers).

Who Should Get a CAC Scan?

Current guidelines suggest considering CAC scoring if you're in the intermediate risk category (10–20% 10-year risk of heart disease) when traditional factors leave uncertainty. You might qualify if you:

• Are age 40–75 with borderline or intermediate risk.
• Have a family history of early heart disease.
• Smoke or are a long-term smoker.
• Have diabetes or metabolic syndrome—but only if your risk assessment remains unclear.

It's generally not recommended for people at very low risk (under 5% 10-year risk) or those already diagnosed with heart disease.

Benefits and Limitations

Benefits

• Personalizes risk beyond age, blood pressure and cholesterol.
• Can motivate lifestyle changes.
• Helps decide on preventive medications (e.g., statins, aspirin).

Limitations

• Doesn't detect non-calcified (soft) plaque.
• Involves a small amount of radiation.
• Not a one-time "yes/no" test—retesting isn't routinely recommended unless it changes management.

What to Do After Your Score

Regardless of your CAC score, there are steps you can take to protect your heart:

1. Lifestyle Changes

   • Eat a heart-healthy diet (plenty of fruits, vegetables, whole grains).
   • Exercise regularly (at least 150 minutes of moderate activity per week).
   • Quit smoking and limit alcohol.
   • Maintain a healthy weight.

2. Medications (as advised by your doctor)

   • Statins to lower LDL ("bad") cholesterol.
   • Aspirin for certain high-risk individuals.
   • Blood pressure–lowering drugs if needed.

3. Follow-Up

   • Regular check-ups to monitor risk factors.
   • Repeat imaging only if it will change your treatment plan.

When to Seek Medical Advice

If you experience any of the following, don't wait—seek care immediately:

• Chest pain or discomfort.
• Shortness of breath.
• Sudden dizziness or fainting.
• Unexplained fatigue or sweating.

If you're noticing milder symptoms like occasional chest discomfort, unusual fatigue, or other concerning changes in your health, you can use a free AI symptom checker to help determine whether you should schedule an appointment with your healthcare provider.

Final Thoughts

A coronary artery calcium score is a valuable tool for refining your heart disease risk. It can help you and your doctor decide on the most appropriate prevention strategies—whether that's lifestyle changes, medications, or more frequent monitoring.

Remember: this test is just one piece of the puzzle. Always speak to a doctor about any concerns or serious symptoms. They can interpret your score in the context of your overall health and guide you toward the best next steps.