Study Design: This proposal will be conducted in two phases. Phase 1 will accomplish Specific Aim 1, 2, and 3. Patients with newly diagnosed breast cancer awaiting definitive surgery, will be enrolled pre-operatively and undergo arm measurements and complete the LBCQ and the DASH surveys. These same study procedures will be completed at 1, 3, 6, 12, 18, and 24 months postoperative. Documentation collected during the study will include: demographic information; co-morbid conditions; operative and pathology reports; and use of adjuvant therapies such as chemotherapy, hormonal therapy, and radiation therapy. Incidence rates of lymphedema and the impact of extent of surgery and radiation therapy will be determined. We will also use this information to develop a simple screening tool to identify patients that will develop lymphedema prior to the development of significant limb volume changes. Specific Aim 4 is Phase 2 of the proposal. A high risk population (those that have an axillary node dissection and radiation therapy) will be randomized to standard education versus standard education, compression sleeve, and exercise. The effectiveness of prevention to reduce incidence and severity of lymphedema and the impact on symptoms and functional impairment will be determined. This work will move toward a new paradigm of lymphedema management with a simple screening tool to identify high risk patients before significant swelling occurs and investigate prevention strategies to decrease the incidence of lymphedema.