(HealthDayNews) -- We spend about one-third of our lives asleep, but sometimes sleep can be elusive.
Almost everyone has had transient insomnia -- the inability to fall asleep once in a while, or waking up feeling tired.
Chronic insomnia lasts longer. The common condition may be brought on by medical or psychiatric causes, such as colds, pain or depression. But 10 percent of all insomnia occurs in the absence of any medical or psychiatric disorder, and is called primary insomnia.
Duke University offers these good sleep habits:
If these habits aren't working, tell your doctor. More assessment and treatment may be needed.