Who Is At Risk for Narcolepsy?

Narcolepsy may affect 150,000 (1 in 2,000) people or more in the United States. It usually first occurs between the ages of 15 and 30 and affects both men and women. The symptoms can start suddenly or appear gradually. The condition is difficult to diagnose without medical tests. Often people live with mild symptoms, such as daytime sleepiness and muscle weakness, for several years before narcolepsy is diagnosed. Narcolepsy can also develop later in life or in children, but it is rare before age 5. Factors that may increase the risk of developing narcolepsy include having:

• A brother, sister, or parent with narcolepsy
  
• Certain thyroid disorders
  
• Diabetes
  
• A disease in which the body’s infection fighting system mistakenly attacks the body’s own organs and tissues (an autoimmune disorder)