Please note: This information was current at the time of publication. But medical information is always changing, and some information given here may be out of date. For regularly updated information on a variety of health topics, please visit, the AAFP patient education website.

Information from Your Family Doctor

Lung Nodules


Am Fam Physician. 2009 Oct 15;80(8):834.

  See related article on pulmonary nodules.

What is a lung nodule?

A lung nodule is a small, ball-shaped mass that can grow in the lung. Your doctor can see it on a chest x-ray or CT scan. Nodules can be smaller than a pea, the size of a golf ball, or even larger. They are often found when patients have tests for other reasons (such as x-rays to look for pneumonia).

Does a lung nodule mean I have cancer?

Not all nodules are cancer. A lung nodule can be benign (bih-NINE), which means it's not cancer, or malignant (muh-LIG-nent), which means it is cancer or may turn into cancer. Some patients are at higher risk of malignant lung nodules. Patients who smoke or have smoked in the past, who are older than 40 years, and who have other types of cancer are at higher risk of getting lung cancer.

What tests will my doctor do?

Your doctor will look at x-rays and CT scans of your chest to check a lung nodule. He or she may also look at old x-rays and CT scans to see if the nodule has changed over time. If more information is needed, your doctor may do another type of scan—a positron emission tomography scan (also called a “PET scan”).

Sometimes your doctor will do a biopsy of the lung nodule. A biopsy is when your doctor takes a small piece of tissue from inside your lung to look at it more closely.

What if my doctor thinks the nodule is benign?

You doctor may watch the nodule over time with several CT scans. The scans may be done three, six, or 12 months apart to make sure that the nodule is not growing.

What if my doctor thinks the nodule is malignant or growing?

Your doctor may send you to a lung or cancer specialist if your nodule is growing or if it may be malignant. The specialist might do a biopsy to find out if the nodule is cancer.

Where can I get more information?

Your doctor

American College of Chest Physicians

Web site:

American College of Radiology

Web site:

This handout is provided to you by your family doctor and the American Academy of Family Physicians. Other health-related information is available from the AAFP online at

This information provides a general overview and may not apply to everyone. Talk to your family doctor to find out if this information applies to you and to get more information on this subject.


Copyright © 2009 by the American Academy of Family Physicians.
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