The physician will be sure to ask when the swelling began, whether there is a history of surgery, trauma, radiation, or new medication before the swelling, if there are other symptoms, whether the swelling is constant or intermittent, and if anything improves the swelling. A physical examination is also mandatory. If you are at risk for lymphedema, for example, if you have recently undergone cancer surgery involving your lymph nodes, your doctor may diagnose lymphedema based on your signs and symptoms. If the cause of lymphedema is not so clear, your doctor may order imaging tests to look at your lymphatic system. Tests may include:

Magnetic Resonance Imaging: An MRI, which uses a magnetic field and radio waves, will give the physician three-dimensional, high-resolution images of the tissue involved.

Computed Tomography: This X-ray technique produces detailed, cross-sectional images of body structures. CT scans can reveal blockages in the lymphatic system.

Ultrasound: This test uses sound waves to produce images of internal structures. It can help find blockages within the lymphatic and vascular systems.

Lymphoscintigraphy: During this test, a radioactive dye is injected into the person, and then they are scanned by a machine. The resulting images show the dye moving through the lymph vessels and reveal any blockages.