Aims and intended learning outcomes The aim of this article is to provide an overview of the underlying physiology of the causes of common leg ulcers, thus giving the nurse a rationale for the appropriate assessment and treatment of these wounds. After reading this article you should be able to: ■Discuss common causes of leg ulcers ■Distinguish between venous and arterial ulceration ■Outline the types of assessments used to determine aetiology of leg ulcers ■Provide a physiological rationale for different treatments.