Lymphoedema is a feared disease, associated with the treatment for breast cancer. It is typically characterised by regional swelling (in one or both arms, breast and/or trunk) due to excess accumulation of protein-rich fluid in body tissues. The presence of lymphedema leads to upper-body morbidity, as well as physical, functional, social and psychological concerns. Findings from a meta-analysis suggest that 21% of women will develop lymphedema following breast cancer. Lymphoedema incidence seems to increase over time, at least up to 24 months after breast cancer, with new cases presenting beyond this period at a much slower rate. The odds of developing lymphedema are about 4 times higher for those who have had axillary lymph node dissection compared with those who underwent sentinel node biopsy. There is also consistent evidence that lends support to several other risk factors for lymphoedema, including more extensive surgery, a high body-mass index, adjuvant therapy, and low physical activity. Understanding risk factors provides information about potential targets for future prevention and management strategies with incorporating physical activity and exercise, as well as weight management strategies into standard breast cancer care worthy of future investigation. Given that the incidence of breast cancer worldwide is increasing, understanding the incidence of subsequent secondary lymphoedema and its associated risk factors is clearly of public health importance.