Final answer:
Narcolepsy is a sleep-wake disorder characterized by an uncontrollable need to sleep, often paired with cataplexy and hallucinations, distinguishing it from other sleep disorders such as insomnia and sleep apnea.
Step-by-step explanation:
Narcolepsy is a sleep-wake disorder that involves an uncontrollable need to sleep. Unlike insomnia disorder, which is characterized by difficulty falling or staying asleep, or sleep apnea, where breathing stops intermittently during sleep, narcolepsy is notable for causing sufferers to fall asleep at inopportune times during the day. Symptoms often include cataplexy (a lack of muscle tone or muscle weakness) and sometimes vivid, dream-like hallucinations during these sleep attacks. Although narcolepsy can present a variety of symptoms and the efficacy of treatment can vary, it is distinct from other sleep disorders like hypersomnolence disorder, which is characterized by excessive sleepiness despite having a main sleep period that lasts at least 7 hours.