Breast Cancer Care > L-Dex

L-Dex is a test that is measured on patients who have undergone an axillary lymph node dissection or sentinel node biopsy during surgery.  This test measures the likelihood that the patient will develop a condition known as Lymphedema.  This is an abnormal buildup of fluid that causes swelling, most often in the arms or legs. The condition develops when lymph vessels or lymph nodes are missing, impaired, damaged, or removed. Lymphedema in relation to breast cancer occurs as a result of a blockage or interruption that alters the flow of lymph through the lymphatic system and can develop from an infection, malignancy, surgery, scar tissue formation, trauma, deep vein thrombosis (blood clot in a vein), radiation, or other cancer treatment.

L-Dex measurements are a quick, non-invasive and sensitive method for aiding in the clinical assessment of lymphedema of the arm. L-Dex measurements can help your healthcare professional accurately monitor lymphedema whether in the early (hidden) or late stages. L-Dex measurements made each time you see your healthcare profesional can help them: 


– Better clinically assess the early stages of lymphedema
– Show you how any treatment or management is working

How is L-Dex measured?

     L-Dex measurements are made by passing a harmless electrical signal of very low strength from the L-Dex device through your arm. Both arms are measured and the whole procedure takes only minutes to complete. You will not feel the test and the signal is harmless.

What does an L-Dex value mean?

      The L-Dex value indicates the difference in the amount of fluid in the unaffected arm and affected arm.  L-Dex values are displayed against a normal “healthy” range (see diagram below). L-Dex values greater than 10 or an increase of 10 L-Dex units may be indicative of lymphedema. L-Dex values indicative of lymphedema should decrease as a result of therapy.












If lymphedema does occur, please consult with your doctor, and treatment options will be discussed.

L-Dex testing is not covered by Medicare or private insurances at this time.