Primary insomnia is a sleep disorder that is characterized by difficulty in falling or staying asleep, or poor sleep quality, with no underlying medical or psychiatric condition. Some synonyms for primary insomnia are sleeplessness, chronic insomnia, idiopathic insomnia, and sleep disturbance. Sleeplessness refers to the inability to fall or stay asleep, while chronic insomnia implies that the condition has persisted over a long period. Idiopathic insomnia means that the cause of the sleep disorder is unknown, and sleep disturbance is a general term for any interruption or alteration of the sleep cycle. Regardless of the term used, primary insomnia can have a significant impact on one's health, mood, and daily functioning, and prompt medical attention may be necessary.