Insomnia is highly prevalent in clinical practice and can present independently or alongside other medical and mental health disorders. Insomnia is a risk factor for the development and exacerbation of medical and mental health conditions. Behavioral and pharmacological treatments for insomnia are available. In this article, we review important mechanisms associated with insomnia including the hyperarousal model of insomnia and the neurobiology of insomnia. We then review the treatment approaches and management strategies for insomnia including cognitive behavioral therapy for insomnia, transcranial magnetic stimulation, pharmacologic treatment, and adjunctive treatments for insomnia.