9.1 Narcolepsy

Have you ever seen someone fall asleep suddenly while walking or eating? There are some people who cannot stay awake if they are sleepy.  For example, a woman fell down like a log while walking on the street and started snoring. And a man fell asleep with his face in a dish while eating at a restaurant. This is very different from taking a nap. In fact, it’s a serious disease known as narcolepsy. The most common symptoms of narcolepsy are sleepiness during the day and sudden sleep attacks. Nobody is sure what causes narcolepsy. However, it seems to be related to a genetic factor. Narcolepsy can cause dangerous situations if people suffering from it fall asleep while driving or crossing the road. It is estimated that about three million people worldwide suffer from narcolepsy.