This chapter aims to provide a generic framework for the assessment and understanding of symptoms in advanced disease. It emphasises an integrated approach, recognising that various symptoms are often related. In understanding symptom assessment, the distinction between symptom occurrence and symptom distress is important. Symptom occurrence refers to perceptions about the frequency, duration, and severity of a symptom. In contrast, symptom distress refers to the impact of the symptom on the person in terms of the degree to which that person has to alter his or her daily life in response to the symptom, and the extent to which the symptom or its impact causes physical or mental suffering. Quality is also critical in providing an indication of the experience of the symptom through the use of such words as 'horrible', 'frightening', or 'intolerable'. Timing includes the symptom's onset, pattern, and frequency. The region of a symptom refers to the part of the body affected.