What sleep disorder is characterized by difficulty falling or staying asleep?

Insomnia is characterized by difficulty falling asleep, staying asleep, or waking up too early and not being able to go back to sleep. This condition can result in decreased sleep quality and can significantly impair daily functioning. People suffering from insomnia often experience symptoms such as fatigue, mood disturbances, and difficulty concentrating, all of which can stem from prolonged sleep deprivation.

While hypersomnia involves excessive sleepiness or prolonged sleep periods, narcolepsy is marked by uncontrollable sleep attacks and sudden sleep onset, often during the day. Sleep apnea, on the other hand, is characterized by interruptions in breathing during sleep, leading to repeated awakenings and fragmented sleep. In each of these cases, the primary symptom is not the difficulty in falling or staying asleep, which distinctly defines insomnia.