Insomnia is repeated difficulty going to sleep or staying asleep, or both.
Narcolepsy is a sleep disorder, which causes excessive and overwhelming daytime sleepiness, even after getting plenty of nighttime sleep. If you have narcolepsy, you are likely to become drowsy or to fall asleep at inappropriate times and places.
Sleep apnea is a breathing disorder characterized by brief interruptions of breathing during sleep. It is a serious, potentially life-threatening condition and happens in all age groups and both genders, although it is more common in men.