This chapter, written for undergraduate medical students and post-graduate doctors in training, presents information on how to manage tiredness — a case which they are likely to encounter in the future in a general practice setting. It presents the case of a 17-years old reluctant patient brought by his mother because she thinks he is more tired than usual. His mother has noticed that in the last 6 months or so he has had difficulty getting up in the morning to go to college, has fallen asleep while doing his homework and is not taking part in football or any sports as much as before. 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.