It's well documented that the United States is a nation of sleep deprivation. But sleep issues differ significantly between men and women, with women more frequently fighting insomnia, CBS News reported on Monday.

Women, in addition to suffering from insomnia more frequently, also toss and turn more in their sleep due to hormone fluctuations. The sleep cycle is extended by estrogen, which is why woman say they have trouble sleeping during menstruation, menopause or pregnancy.

A poll by the National Sleep Foundation found that only 54 percent of men find it hard to fall asleep a few times per week, compared to 63 percent of women. Daytime exhaustion also hit women more often than men.

"One of the things is the internal clock controls the timing of sleep," said Czeisler. "It runs faster in women than it does men. It's only about a tenth of an hour but it adds up so that women, in general, their internal clocks are set to about an hour or an hour and half earlier than men, and that means it wakes them up earlier in the morning and it's harder to stay awake in the evening."

On the other hand, men were more likely to experience sleep apnea due to physical differences like fat accumulated around the neck. Only 9 percent of women compared to 17 percent of men have sleep apnea, which is a sleep issue that causes breathing disruptions.

"If you crowd out the airway then you're going to have trouble when you sleep," said Czeisler.

Regardless of gender, everyone should get between seven and nine hours of sleep to preserve proper cognitive function and sharp motor abilities. Exercise, sticking to a regular sleep schedule and other health habits can help people fall asleep, Psych Central reported.