Lung Nodules
The CT scan shows a small nodule in your lung – A guide to follow-up for pulmonary nodules.
Small nodules are usually scars.
It is very common to find small lung nodules during a health checkup chest CT, and most of them are scars left by past inflammation (such as tuberculosis) or benign lesions.
- The risk level of a nodule is assessed based on its size, shape, border, and smoking history. If it is small and has smooth borders, the risk is low.
- Most prescriptions involve "a follow-up CT scan in several months to 1 year." A follow-up CT scan is the most reliable way to check if the nodule is growing, so don't forget to have it done.
- Ground-glass opacity (GGO) nodules tend to grow slowly and may require longer periods of monitoring.
Source: 질병관리청 국가건강정보포털 · as of 2026-08-13
If you're concerned about lung cancer, check if you meet the screening criteria.
Individuals aged 54 to 74 years old, with a smoking history of 30 pack-years or more (e.g., one pack per day for 30 years) are eligible for the national lung cancer screening program (low-dose CT scan every 2 years). If you meet these criteria, be sure to participate. Above all, quitting smoking is the best way to reduce your risk of lung nodules – call the smoking cessation hotline at 1544-9030, and free support is available through public health centers' smoking cessation clinics.
Source: 질병관리청 국가건강정보포털 · as of 2026-08-13
Frequently asked questions
Is it dangerous to have frequent contrast-enhanced CT scans because of the radiation exposure?
For follow-up examinations, low-dose CT scans are primarily used, as the risk of missing a nodule is much greater than the risks associated with the examination itself. It is only necessary to adhere to the recommended schedule.
You have a nodule, but why aren't you doing a biopsy?
Small nodules are difficult to access with a needle, and the benefits of intervention may not outweigh the risks of complications, making it more accurate to monitor whether they are growing. If they increase in size or change shape, then biopsies, PET scans, etc., can be performed at that time.
Sources for this page
· 질병관리청 국가건강정보포털 (as of 2026-08-13)Last checked: 2026년 8월 13일
Rules and costs can change. Before you make an important decision, check the official page for the latest information.