Historically, breast cancer-associated lymphedema has been relatively ignored, with mis-diagnosis, late diagnosis, and failure to treat. The condition has a measurable, substantial impact on patient function and perceived quality of life (QOL). Recent pilot studies suggest that interventions that are designed to facilitate early diagnosis and preventive strategies have a major impact on the incidence and severity of disease burden. This registry is designed to prospectively capture the relevant data to document the impact of preemptive diagnostic and treatment strategies.