Narcolepsy is a rare, life-long disabling neurological disorder that affects 1 in 3000 individuals. It is characterised by excessive daytime sleepiness and presents as a result of a loss of hypothalamic hypocretin producing neurons. A cohort of sufferers also exhibit a sudden loss of muscle tone while awake triggered by strong emotions, termed cataplexy. Patients with narcolepsy can also experience disturbed night time sleep, sleep paralysis, hypnagogic hallucinations and/or hypnopompic hallucinations. The term hypnagogic describes the period when an individual falls asleep, whereas hypnopompic describes the period when a person awakens. The onset of narcolepsy is often seen during early adolescence or adulthood. The rate of concordance in monozygotic twins for NT1 onset is 20- 30%. Onset of the condition in a first-degree relative of a NT1 sufferer is approximately 1-2% and the relative risk for a first-degree family member of a NT1 sufferer is 10- to 40-fold higher than the general population Narcolepsy has a severe impact on the quality of life for sufferers. Excessive daytime sleepiness consists of periods of an irrepressible need to sleep during times which would normally be characterized by wakefulness, leading to sleep attacks that are promoted by sedentary activities and physical inactivity. Furthermore, symptoms of narcolepsy may cause complications in relationships and family life. Narcolepsy often goes undiagnosed for many years and even following a diagnosis, it can still take time to understand and manage symptoms. Female sufferers who become pregnant may have to alter current medication as some have been shown to pose risks to the unborn child.