A Spot on Your Lung Scan: What a Lung Nodule Means and What Happens Next
November 9, 2026 · Lung Cancer, Cancer Information
Being told there's a "spot" or "nodule" on your lung scan is frightening. It's also very common, and the most important thing to know is this: most lung nodules are not cancer. Here's what a nodule is, what doctors look at, and what usually happens next. November is Lung Cancer Awareness Month, a good time to understand the process.
What a lung nodule is
A lung nodule is a small abnormal area in the lung, 3 centimeters (about 1.2 inches) across or smaller. Nodules usually show up on a CT scan of the chest or belly. Many are found by chance on a scan done for some other reason, such as checking for pneumonia or after an injury. Doctors call these "incidental" nodules.
Nodules are often caused by things that aren't cancer, such as an old infection or scar tissue.
What makes doctors look closer
According to the American Cancer Society, doctors weigh several features to estimate how likely a nodule is to be cancer:
- Size. Larger nodules are more concerning than very small ones.
- Shape and edges. Smooth, round nodules are less worrying than irregular ones.
- Location in the lung.
- How it looks: solid, or hazy (sometimes called "ground glass").
- Whether it grows on follow-up scans. Growth is one of the most important signs.
Your own risk factors matter too, such as your age, whether you've smoked, and your family and work history. Be sure your doctor knows them.
What usually happens next
Watching with repeat scans
For many nodules, the next step is simply another CT scan, usually anywhere from a few months to a year later, depending on how likely the nodule is to be cancer. If it hasn't changed, you may need a few more scans over time. This "watchful waiting" can feel nerve-racking, but for small, low-risk nodules it's usually the safest approach, because it avoids procedures you may not need.
A PET scan
If the nodule has grown, a PET scan may help show whether it's likely to be cancer. PET scans use a small amount of a radioactive sugar that tends to collect in active cells, such as cancer cells.
A biopsy
If the nodule keeps growing or has other worrying features, a biopsy is recommended to take a small sample of tissue. It can be done in several ways:
- with a bronchoscope, a thin tube passed through the mouth or nose into the airways;
- with a needle through the chest wall, guided by a CT scan;
- during surgery.
If the biopsy shows no cancer, some nodules are still checked with a CT scan every 6 to 12 months for a few years. If it shows an infection, you may be referred to an infectious disease specialist.
Questions to ask your doctor
- How big is the nodule, and what does it look like?
- How likely do you think it is to be cancer, and why?
- When should I have my next scan, and who will order it?
- What would make you recommend a PET scan or a biopsy?
- Should I see a lung specialist (pulmonologist) or a thoracic surgeon?
Don't let the follow-up slip
The biggest risk with a nodule is often not the nodule itself but a missed follow-up scan. Put the date on your calendar, ask who is responsible for scheduling it, and call if you haven't heard anything. If your nodule was found by chance in an emergency room or during a scan for something else, make sure your primary care doctor knows about it.
While you wait, call your doctor if you develop new symptoms such as a cough that won't go away, coughing up blood, chest pain or shortness of breath. Learn more about lung cancer symptoms, and find imaging centers and specialists in our directory.
The bottom line
A lung nodule is a reason to follow up, not a reason to panic. Most are harmless. The key is making sure each recommended scan happens on time, so that the rare nodule that is cancer is found early.
This article is for general information and is not medical advice. Talk with your doctor about your own situation.