Although sleep needs vary from person to person, we adults need about seven to nine hours of sleep every night to be at our best, both mentally and physically [source: National Sleep Foundation]. But, in reality, about 29 percent of Americans get fewer than seven hours of sleep a night. If you're not regularly getting your eight hours, consider this: Getting fewer than seven hours of sleep a night raises your risk of catching a cold threefold, as compared to people who average eight hours a night [source: Engel].
And if you've already caught a cold? Staying well rested will give your body a chance to focus on getting well.