Specific Aims: 1) Evaluate patients both pre-operatively and at specific time intervals post-operatively to establish the incidence of lymphedema in sentinel lymph node biopsy and axillary dissection groups. 2) Create a simple screening tool using arm measurements, symptoms identified by the LBCQ, and treatment and staging information to identify patients that should go on to further testing and treatment. 3) Utilize the DASH survey to measure the extent of disability from lymphedema and surgical treatment. 4) Conduct a randomized trial of lymphedema prevention in a high-risk breast cancer population.