What is insomnia?
Insomnia is difficulty falling asleep or staying asleep and is often characterized by impairments in daytime functioning. People with insomnia often complain of impairments in attention, memory or concentration, impairments in their mood, feeling depressed or irritable or anxious, and impairments in their ability to function in the workplace, at home or even at school.
What determines "adequate sleep?"
Adequate sleep is characterized by two things. One is enough sleep time-that's getting into bed, falling asleep quickly and staying asleep throughout the sleep period. The other thing is good quality sleep. That's a little more difficult to measure, but people know they've had good quality sleep when they wake up feeling rested and refreshed and ready to start the day.
How prevalent are sleep problems in the US?
Sleep problems are quite common. Perhaps more than half of all Americans experience a sleep problem at some time in their lives. Somewhere between 9 and 17% of the adult population will experience chronic or more ongoing difficulties with their sleep.
Are certain types of people more prone to sleep problems than others?
Insomnia affects older people more than it does younger people. It's more often reported in women, and it may be associated with certain medical or psychiatric conditions.