Heart artery calcium found by chance on chest CT

The main guidance

BSCI/BSCCT and BSTI consensus (UK, 2021): review the heart on every CT where it is seen, grade coronary calcium as none, mild, moderate or severe, and add simple next steps to the report. It applies to scans with and without contrast. (BSCI/BSTI 2021)
SCCT/STR guideline (US, 2016): on coronary calcium scoring of noncontrast chest CT scans done for reasons other than the heart. (SCCT/STR 2016) Reviews summarise it as calling for calcium to be scored or graded on all such scans, whatever the reason for the scan. (CAC-DRS primer 2023)(Doyle 2025)
CAC-DRS (SCCT, 2018): a standard way to report coronary calcium on all noncontrast CT scans, whatever the reason for the scan, with general next steps by category. (CAC-DRS 2018)

Who it applies to

Adults who had a chest CT for another reason, such as a lung problem or a lung cancer screening scan. The USPSTF lists coronary artery calcification among the common incidental findings on lung cancer screening scans. (USPSTF 2021) The UK consensus sets no upper age limit for reporting it, and says a known stent or bypass already shows heart artery disease, so the calcium need not be assessed then. (BSCI/BSTI 2021)

How it is graded on a chest CT

Coronary calcium grades on a chest CT and the matching CAC-DRS category (simplified)
Visual grade	What it looks like	CAC-DRS	Agatston score on a dedicated scan
None	No calcium seen	0	0
Mild	Only isolated flecks of calcium in a segment of an artery	1	1 to 99
Moderate	More than mild, less than severe	2	100 to 299
Severe	Continuous deposits of calcium along a segment	3	Over 300

The descriptions, categories and score ranges are as given in the CAC-DRS primer, which notes that studies have used different methods to split mild, moderate and severe. (CAC-DRS primer 2023) CAC-DRS may add an A (from an Agatston score) or V (from a visual grade), and N1 to N4 for how many of the four main heart arteries have calcium, for example V1/N2. (CAC-DRS primer 2023) For what a full calcium score means, see coronary calcium score results.

What usually comes next

A heart risk check, not usually more scans: the UK consensus says coronary calcium on a chest CT is a frequent finding and not necessarily a reason for more imaging or a cardiologist referral. It recommends a review of symptoms and heart risk factors, usually by your GP or the doctor who asked for the scan. (BSCI/BSTI 2021)
No symptoms: the UK consensus says there is no current evidence to support further imaging such as stress tests, CT coronary angiography or invasive angiography. (BSCI/BSTI 2021)
Symptoms such as chest pain: assessment under standard chest pain guidelines. (BSCI/BSTI 2021)

Heart risk checks usually include blood pressure and a cholesterol test; see heart screenings by age.

Is a separate calcium score scan needed?

A dedicated calcium score scan is timed to the heartbeat (ECG-gated); most chest CTs are not. (BSCI/BSTI 2021) The CAC-DRS primer says the visual grade on a non-gated scan compares well with a full score but is not sufficient to replace it. (CAC-DRS primer 2023) The UK consensus does not recommend more imaging for people without symptoms. (BSCI/BSTI 2021) Whether a separate scan would change anything for you is for you and your doctor.

What the finding does and does not show

Calcium is a marker of heart artery disease, but a lot of calcium can be present without a narrowing that limits blood flow, and heart artery disease can be present without calcium. (BSCI/BSTI 2021)
The UK consensus says not to call it "normal for age", as risk rises with the amount of calcium at every age, and that severe calcium under age 40 is unusual. (BSCI/BSTI 2021)
It is often missed in reports: studies find it on 20 to 65% of these scans, and one 2025 audit found reports said present or absent with no grade. (Doyle 2025)

MedlinePlus, when to contact a medical professional: (MedlinePlus)

If you have any risk factors for CHD, talk to your provider about prevention and possible treatment steps.

Contact your provider, call 911 or the local emergency number or go to the emergency room right away if you have:

Angina or chest pain
Shortness of breath
Symptoms of a heart attack
Sudden loss of consciousness

Routine age-based screening

A finding on a scan does not replace the routine screenings for your age. If the same scan showed a spot on the lung, see lung nodule found by chance.

Where they differ:

How to grade it. The UK consensus recommends only a simple visual grade for the whole heart, since a full score needs dedicated software and training. (BSCI/BSTI 2021) CAC-DRS allows either a visual grade or an Agatston score and adds the number of arteries involved. (CAC-DRS 2018)(CAC-DRS primer 2023) One 2025 study says a reliable Agatston score is not possible on standard non-gated chest CT. (Doyle 2025)
Scans with contrast. The UK grade applies to scans with and without contrast; the SCCT/STR guideline and CAC-DRS are written for noncontrast scans. (BSCI/BSTI 2021)(SCCT/STR 2016)(CAC-DRS 2018)
Further tests. The UK consensus sees no evidence for more imaging without symptoms. (BSCI/BSTI 2021) The authors of the 2025 study suggest some hospital patients with moderate or severe calcium may merit an outpatient CT coronary angiogram. (Doyle 2025)
How much it helps. In a 2023 US trial, telling doctors and patients about calcium on an earlier chest CT led to more heart testing (15.1% vs 2.3%), and the authors say more research is needed on whether this lowers heart events. (NOTIFY-1 2023) The USPSTF says the balance of benefits and harms of incidental findings on lung cancer screening scans is uncertain. (USPSTF 2021)

Your doctor decides what your result means for you.

Questions people ask

Does calcium in my heart arteries mean I have heart disease?

The UK consensus suggests the report say the calcium indicates the presence of coronary artery disease. It also says this is a frequent finding and not on its own a reason for more scans or a cardiologist referral. (BSCI/BSTI 2021)

Do I need a separate calcium score scan?

Not usually. The UK consensus says there is no current evidence for further imaging in people without symptoms. A review notes the chest CT grade is useful but not a full replacement for a dedicated scan; your doctor decides. (BSCI/BSTI 2021) (CAC-DRS primer 2023)

My report says mild. Is that normal for my age?

The UK consensus says the term normal for age should be avoided, because the risk of heart events rises with the amount of calcium at every age. (BSCI/BSTI 2021)

My report did not mention the heart. Does that mean no calcium?

Not always. Studies find calcium on 20 to 65% of these scans, and it is often not reported. You can ask your doctor whether the heart was reviewed. (Doyle 2025)

What if I have chest pain?

The UK consensus says people with symptoms should be assessed under chest pain guidelines. MedlinePlus says to call 911 or go to the emergency room right away for chest pain or symptoms of a heart attack. (BSCI/BSTI 2021) (MedlinePlus)