Anyone can get narcolepsy, but some things may make it more likely. People who have a history of insomnia in their family are more likely to get it themselves, which suggests a genetic link. It usually starts in youth or early adulthood, but it can happen at any age. People who have autoimmune diseases may also be more likely to get narcolepsy type 1. This is because the loss of neurons in the brain that make hypocretin may be caused by an autoimmune reaction. In people who are more likely to get it, environmental factors like infections or worry may speed up the process. Early detection of signs, such as being sleepy during the day and losing your temper, is important for diagnosis and treatment.