The history and examination are the cornerstones of an evaluation of the patient who has sleep-related complaints (insomnia, excessive sleepiness (ES), and parasomnias). This chapter provides clinicians with tools to feel more confident in evaluating and treating sleep complaints themselves, and recognize symptoms and signs that may suggest referral to a sleep medicine specialist is indicated. Many of the symptoms and behaviors that are necessary for the completion of the history occur during sleep, or during periods of extreme sleepiness, making the patient's own account unreliable. Therefore, it is helpful to obtain this information from bed partners and family members. Co-morbid disorders should be reviewed, along with their dates of onset, types of treatment, and results of treatment. Several social or occupational factors can contribute to sleep-related complaints, necessitating evaluation. The chapter outlines some of the more commonly encountered sleep disorders that are related to insomnia and ES.