This article provides an overview of the current definitions, diagnostic tools, and overall management of insomnia.The treatment of insomnia has shifted over time, with a growing emphasis on nonpharmacologic therapies as a first-line intervention and the leveraging of technology to aid in the dissemination of these therapies. With this evolution, the definition of insomnia has changed to reflect a common treatment pathway. As pharmacologic treatment options have increased, so has concern about the dangerous short-term and long-term adverse effects of these treatment options.Insomnia is a common disorder, frequently overlapping with other neurologic and psychiatric disorders, which can cause significant distress and disruption to patients' lives. Nonpharmacologic therapies are highly effective and are now considered first-line treatments. Although efficacy is variable, numerous pharmacologic interventions are available, and many options come with considerable concern about adverse effects, particularly in populations over 65 years old.