Most likely at one time or another, you have had a rough night of sleep. But if you consistently have difficulty falling asleep or sleeping through the night, then you might suffer from insomnia.
According to the National Sleep Foundation, 48% of Americans report insomnia occasionally, while 22% experience insomnia nearly every night. Women are 1.3 times more likely to report insomnia, and people over the age of 65 are 1.5 times more likely to complain of insomnia than younger people. Divorced, widowed, and separated couples also report more frequent cases of insomnia. (Not sure how much sleep you should be getting? Check out this article from the National Sleep Foundation.)
So, what causes this sleep disorder?