A variety of different tests and procedures may be used to detect and diagnose lung cancer. In addition to laboratory tests of blood, urine and sputum (mucus), tests may include:

• Physical exam and history
• Chest X-ray
• CT or CAT (computerized axial tomography) scan This procedure uses a computer connected to an X-ray machine to obtain detailed pictures of areas inside the body. A dye may be used to help visualize organs or tissues more clearly.
• MRI (magnetic resonance imaging) MRI creates a series of detailed pictures of areas inside the body, using the combination of a powerful magnet, radio waves and computer imaging. 
• PET (positron emission tomography) scan This scan is used to identify malignant cells even before an actual “lump or bump” can be detected in a physical exam, or on CAT or MRI scans. Prior to the scan, a small amount of radionuclide glucose (sugar) is injected into a vein. Because cancer cells divide more frequently than normal cells, they take up more glucose than normal cells and appear brighter in the scan.
• Bronchoscopy A thin, lighted tube called a bronchoscope is guided through the nose or mouth
  into the trachea and lungs. Tissue samples may be taken for biopsy.
• Lymph node biopsy Removal of all or part of a lymph node so that a pathologist can examine the tissue under a microscope to look for cancer cells.
•  Mediastinoscopy A surgical procedure used to examine the organs and tissues between the lungs and nearby areas, for abnormalities. An incision is made near the breastbone and a thin, lighted tube inserted into the chest. Tissue and lymph node samples may be taken for biopsy.

If lung cancer is detected, a treatment plan is developed based on the patient's physical health, what kind of cancer is involved, and whether it has spread.