How Is Lung Cancer Diagnosed?

How lung cancer is diagnosed differs from person to person. Your medical team chooses tests based on several factors:

  • Your medical history
  • Your symptoms
  • Findings from your physical exam and test results

Imaging Tests

Your doctor might order imaging tests that may help find lung cancer. Imaging tests make pictures of the inside of your body. These pictures help doctors to find lung cancer, to see if it has spread, to see if treatment is working or to find a cancer that has come back after treatment. These tests include:

A CT (or CAT) scan is a special kind of x-ray that takes many pictures as you lie on a table that slides in and out of the machine. A computer then combines these pictures into a detailed picture of a slice of your body. 

Learn more about CT scan.

For a PET scan, a form of radioactive sugar isotope is injected into the blood. Cancer cells in the body absorb large amounts of the sugar. A special camera can then detect the radioactivity. This test can helps determine whether the cancer has spread to the lymph nodes or other parts of the body.


To see if something suspicious is actually lung cancer, the doctor must study tissue or fluid from or around the lung. Many different procedures allow doctors to remove cells or biopsy from the body and look at them under a microscope to determine if they are cancer. These tests include:

A lighted, flexible tube (called a bronchoscope) is passed through the mouth or nose and into the large airways of the lungs. This test can help the doctor see tumors, or it can be used to take samples of tissue to see if cancer cells are present.

Learn more about bronchoscopy.

For endobronchial ultrasound, a bronchoscope (a thin, lighted, flexible tube) is fitted with an ultrasound device (a device that uses sound waves to make pictures of the inside of your body) at its tip. It is passed down into the windpipe to look at nearby lymph nodes and other structures in the chest. This is done with numbing medicine (local anesthesia) and sedation.  A hollow needle can be passed through the bronchoscope and guided by ultrasound into an area of concern to take biopsy samples. 

Learn more about EBUS.

This test is much like an endobronchial ultrasound, except that an endoscope (a lighted, flexible tube) is used. It is passed down the throat and into the esophagus and used as a guide to evaluate and sample adjacent lymph nodes.

Both of these tests let the surgeon look at and take samples of lymph nodes in the area between the lungs (this area is called the mediastinum).

This test is done to check whether fluid around the lungs is caused by cancer or by some other medical problem. A needle is placed between the ribs to drain the fluid. The fluid is checked for cancer cells.

A small cut is made in the chest. The surgeon then uses a thin, lighted tube connected to a video camera and screen to look at the space between the lungs and the chest wall. The surgeon can see small tumors on the lung or lining of the chest wall and can take out pieces of tissue to be looked at under the microscope. Thoracoscopy can also be used as part of the treatment to remove part of a lung in some early-stage lung cancers. Video-assisted thoracic surgery (VATS) is a new type of surgery that allows surgeons to make very small incisions to view the inside of the chest cavity and potentially remove the cancer.

A sample of mucus you cough up from the lungs (called sputum or phlegm) is examined under a microscope to see if cancer cells are present.

A long, thin (fine) needle is used to remove a sample of cells from the area that may be cancer. The sample is examined in the lab to see if it contains cancer cells.

Under general anesthesia an incision is made in the chest, between the ribs, to obtain a tissue sample or to remove the cancer.

Many researchers are working to develop tests that can make a difference in early lung cancer screening and survival. If you think you are at risk for lung cancer or if you have any symptoms, talk to your doctor about tests to see if you have lung cancer.

Screening for Lung Cancer

Screening is looking for cancer before you have any symptoms, which can help find cancer at an early stage when it may be easier to treat.

Reviewed and approved by the American Lung Association Scientific and Medical Editorial Review Panel.

Page last updated: June 7, 2024

Freedom From Smoking Clinic
Detroit, MI | May 29, 2024
Asthma Basics Workshop - National
, | Jun 18, 2024