Narcolepsy is a chronic sleep disorder characterized by excessive daytime sleepiness and sudden sleep attacks. It is caused by a lack of hypocretin, a chemical that regulates sleep and wakefulness. Symptoms include daytime sleepiness, cataplexy (loss of muscle control triggered by emotions), sleep paralysis, hallucinations, and automatic behaviors. It is diagnosed through polysomnograms and multiple sleep latency tests. While there is no cure, symptoms can be managed through stimulant medications, antidepressants, and lifestyle changes like scheduled napping. Living with narcolepsy presents daily challenges like disrupted sleep, impaired functioning, and social isolation.