Some narcolepsy facts state that anyone, at any age (although most symptoms are usually first noticed in teenagers or younger adults) can develop this sleep disorder that affects the nervous system. Narcolepsy often runs in families with 8 to 12 percent of people with narcolepsy having a close relative with this condition. It can cause excessive sleepiness, including frequent sleep attacks during the day. If you have narcolepsy it can have a huge impact on your active, busy lifestyle. Read more »