Did you ever doubt it? Women have problems with sleep that are unique to them alone:

PMS: 50% of menstruating women report 2 1/2 days per month of disturbed sleep due to “that time of the month.” The number one reason cited: water retention and bloating. The major side effect: insomnia and subsequent daytime tiredness.

Pregnancy: 79% reported disrupted sleep during pregnancy. Difficulty falling asleep and difficuly staying asleep were the number one complaints. How do women cope with the sleep loss? 51% take a nap during the weekday—while 60% nap on weekends.

Menopause: 36% of women respondents reported hot flashes during sleep. Hot flashes disturbed sleep an average of 5 days per month! The most common complaint of women—overall—in relation to sleep? “Unrefreshed upon awakening.”

Source: The National Sleep Foundation’s 1998 Women and Sleep Poll