Excessive Daytime Sleepiness
One of the most prominent symptoms of narcolepsy is excessive daytime sleepiness. People with narcolepsy feel moderately or severely tired during the day. They have difficulty paying attention, concentrating, and staying awake, even if they’ve slept a lot the night before.
People with narcolepsy can start out feeling rested, but have trouble staying awake for long periods of time and fall asleep during routine daytime activities. This is very dangerous, because a person with narcolepsy can fall asleep during an activity like driving, walking, or cooking. Some people fall asleep while performing an activity and continue the activity, with no memory of it later.
Excessive sleepiness is one of the first symptoms to develop in people with narcolepsy. Narcolepsy can be hard to spot, unless a doctor knows how to interpret the symptoms. There are many reasons for extreme sleepiness (lack of proper sleep, sleep apnea, and more), so narcolepsy can go undiagnosed for a long time. This is especially true given that the disorder develops in the teen years, when sleepiness is common.