Insomnia is the most common sleep complaint—30% to 35% of adults experience insomnia. People who have insomnia have trouble falling asleep and staying asleep even when they have the opportunity to get a full night’s rest. Insomnia involves both sleep disturbances and daytime symptoms. Due to a lack of restful sleep, those with insomnia have poor work performance, impaired memory/concentration, and an overall worse quality of life. A board-certified sleep medicine doctor can diagnose and treat insomnia.