The problem of weakness in patients with advanced cancer

Weakness is a disabling symptom present in the majority of patients with advanced cancer. However, as a subject for research, it has received low priority status. Weakness and fatigue are terms that are often used synonymously and are likely to be part of a larger symptom complex and have overlapping aetiologies. This review article addresses the symptom of weakness as a physical aspect of the weakness/fatigue complex. Weakness is compared to and contrasted with fatigue, and the interaction of these two symptoms is discussed. The aetiology of weakness, including the role of cancer cachexia, intrinsic muscle dysfunction, inactivity and drug therapy, is outlined and possible management strategies examined. The role of exercise is controversial and requires further evaluation. Positive approaches to the management of weakness, even in patients without a reversible cause, may help to improve their self-esteem and quality of life.