Diagnosis

If you're at risk of lymphedema — for instance, if you've recently had cancer surgery involving your lymph nodes — your doctor may diagnose lymphedema based on your signs and symptoms.

If the cause of your lymphedema isn't as obvious, your doctor may order imaging tests to get a look at your lymph system. Tests may include:

• MRI scan. Using a magnetic field and radio waves, an MRI produces 3D, high-resolution images of the involved tissue.
• CT scan. This X-ray technique produces detailed, cross-sectional images of the body's 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 obstructions within the lymphatic system and vascular system.
• Lymphoscintigraphy. During this test, the person is injected with a radioactive dye and then scanned by a machine. The resulting images show the dye moving through the lymph vessels, highlighting blockages.