This chapter, written for undergraduate medical students and post-graduate doctors in training, presents information on how to manage muscle pain — a case which they are likely to encounter in the future in a general practice setting. It presents the case of a 58-year-old builder who attended the surgery with generalized joint and muscle pains and weakness of his proximal muscles. The muscle pain and weakness have been slowly getting worse over the last 5 years. His ankles, knees and wrists are painful at all times and he has increasing difficulty in doing his work. The chapter provides details of the patients' medical history and the key findings of clinical examination, together with initial investigation results data for evaluation, and helps them develop their skills of clinical reasoning. Key questions then prompt the student to evaluate the patient, and reach a decision regarding their condition and the possible treatment plan.