Lymphedema is one of the most important long-term side effects in the context of breast cancer. A lymphedema significantly reduces a patient’s quality of life in the long term, both in terms of physical performance and psychosocial interactions. Interdisciplinary work is the primary task of all therapists to minimise the risk through the further development of surgical techniques, to avoid overtreatment, to promote patient education, as well as to diagnose early through screening and to optimise lymphedema therapy further.