Insomnia, defined as trouble falling asleep or staying asleep, is a common problem.
Occasional insomnia is experienced by more than a third of American adults, and chronic insomnia is known to effect more than one in ten. If you have ever suffered from insomnia, you know it can disturb your waking, as well as your sleeping hours. It can cause you to feel sleepy or fatigued during the day, affect your mood, and result in trouble focusing on tasks.

Insomnia can occur in people of all ages.
Most individuals just experience a night or two of poor sleep, but sometimes the sleep disturbance can last for weeks, months, or even years. Insomnia is most common among women and older adults.