Individuals diagnosed with Insomnia have trouble falling asleep, maintaining sleep, and undergoing restful sleep. These symptoms occur for at least one month and are not caused by another sleep disorder, mental disorder, substance use disorder, or general medical condition. Individuals with Primary Insomnia usually complain of a combination of these three symptoms. Insomnia is most common in young adulthood or in middle age people. The onset of Insomnia generally develops during a stressful time. However, even after the stressful period has passed, the non-restorative sleep continues. The course of Primary Insomnia is variable. Some individuals experience intermittent episodes of the symptoms getting better and then worsening again. Meanwhile, others may continue to suffer for more than a year, many years, or indefinitely without treatment.