Many women develop lymphedema, painful swelling in the hand or arm, after treatment for breast cancer. Various therapies can manage lymphedema, but not cure the chronic condition. As a result, women have to live with side effects including restricted movement in the affected arm and increased risk of infection, and some report reduced quality of life due to increased anxiety, emotional distress and depression. Lymphedema is typically diagnosed by measuring arm volume and/or circumference. But the methods used do not measure changes in lymphatic function. Kirstin Lane is developing a test protocol using lymphoscintigraphy to measure lymphatic function, which could be used to evaluate the effectiveness of current treatments for lymphedema. In addition, exercise was originally believed to exacerbate breast cancer-related lymphedema, but recent research suggests exercise may have a positive impact on lymphatic function. The new test could be used to assess the effects of exercise and to develop appropriate exercise guidelines.