The short answer
This page walks through a lung cancer screening visit, from checking who qualifies to getting results. It is general education, not individual medical advice.
Lung cancer screening uses a low-dose CT scan. CDC says the scan takes only a few minutes and does not hurt.
The USPSTF (2021 final recommendation) advises a yearly scan for adults 50 to 80 who have a 20 pack-year smoking history and smoke now or quit within the past 15 years.
Many scans find small spots that are not cancer. A follow-up scan is common and does not mean you have cancer.
Screening works best as a yearly habit, together with help to quit smoking if you still smoke.
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This page is for anyone who has a lung cancer screening scan coming up, or who is wondering whether to book one. It explains who the test is for, what the visit is like, and what happens after.
Who the test is for
Lung cancer screening is for people at higher risk who have no symptoms. The U.S. Preventive Services Task Force (USPSTF) set the current rules in its final recommendation of March 2021. It advises a yearly low-dose CT scan for adults who meet all three of these:
- Are 50 to 80 years old
- Have a smoking history of at least 20 pack-years
- Smoke now, or quit within the past 15 years
The Task Force says the choice to screen should start with a real talk about the benefits, limits and harms. Many clinics hold this talk at a separate visit before the first scan. CDC reports that only about 18% of eligible U.S. adults have been screened, so it is worth asking if you think you qualify.
Before the scan
Most people need very little preparation. For a chest CT, MedlinePlus says you remove metal jewelry and may change into a hospital gown. Tell the staff if you could be pregnant. If contrast dye is ordered, MedlinePlus says you may be told not to eat or drink for 4 to 6 hours first. Follow your imaging center's instructions.
During the scan
CDC describes the test simply. You lie on a table, and an x-ray machine uses a small amount of radiation to make detailed pictures of your lungs. The table slides through a large ring-shaped scanner. You will be asked to lie still and may be asked to hold your breath for a few seconds.
CDC says the scan takes only a few minutes and does not hurt.
After the scan
A radiologist, a doctor trained to read scans, looks at the pictures. Your care team then shares the results. Ask ahead of time who will contact you and when.
A scan can show a spot that looks abnormal when there is no cancer. This is called a false positive. NCI says it can cause anxiety and is usually followed by more tests, which have risks of their own. Ask your care team what the next step is for you. Our page on lung nodules found during screening explains that process.
Harms to know about
CDC lists three main harms:
- False positives. The test can suggest cancer when none is there.
- Overdiagnosis. The test can find cancers that would never have caused a problem.
- Radiation. Radiation from repeated scans can cause cancer in otherwise healthy people.
That is why screening is limited to people at higher risk, where the benefit is larger.
Keep it yearly
NCI reports that in a large trial, a yearly low-dose CT for three years was better than chest x-rays at finding early-stage lung cancer. USPSTF recommends a scan every year while you still qualify.
Screening does not replace getting checked. If you cough up blood or have severe trouble breathing, get help right away and call 911 if it is severe. For a cough that will not go away or chest pain, call your care team promptly. Do not wait for your next scan.
If you still smoke, NCI says the best way to prevent lung cancer is not to smoke. See our guide to quitting smoking.
Sources
Common questions
Does a lung screening scan hurt?
No. CDC describes the scan as a few minutes lying on a table while an x-ray machine takes pictures of your lungs. It does not hurt. MedlinePlus says you may be asked to hold your breath for a short time.
Do I need to prepare?
Usually very little. MedlinePlus notes that you remove metal jewelry and may change into a gown for a chest CT. Your imaging center will tell you if they need anything else, such as fasting if contrast dye is ordered.
What if they find a spot?
NCI notes that a false-positive result, one that looks abnormal when there is no cancer, can cause anxiety and is usually followed by more tests, which have risks of their own. Ask your care team what the next step is for you.
How often do I go back?
The USPSTF recommends a scan once a year for people who qualify. It says screening should stop once a person has not smoked for 15 years, or if other health problems would make lung surgery unsafe or would greatly shorten life.
Questions to ask your doctor
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Sources last checked: 2026-09-27 what this meansLast updated: 2026-09-27Next planned review: 2027-09-27
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Cancer Explained does not originate medical claims. Every page restates guidance already published by the National Cancer Institute, the CDC, the USPSTF and the FDA, in plain language, with the source cited so you can check the original yourself. AI does the translating and organizing; automated checks test claims, citations, clarity and safety before anything publishes, and this is translation and navigation, not clinical judgment. Nothing here is personal medical advice, and no page can account for your particular situation.
Editorial status: Source checked — This page was written with AI assistance and then compared with the sources listed on it, looking for statements those sources do not back up. That check is not a sentence-by-sentence record and can miss errors. It is not a medical review, and it does not confirm the page is complete or right for your situation.
Human medical review: not completed. Pages here are not signed off by a clinician before they publish. That is not an oversight we are quietly working around: we restate published guidance and cite it, so the authority belongs to the source rather than to us, and every page names where its claims come from — you can verify us instead of trusting us. Where a volunteer clinician has reviewed a page, their name and credentials appear on it; where no name appears, no clinician has checked it. We are glad to have reviewers and are recruiting them, and we do not hold pages back waiting for one. Use this site to understand your situation and to ask better questions of the people treating you.
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