That bug that's going around? Until it's moved to the next zip code, put yourself to bed early.

In a 2-week study, getting a little less sleep -- under 7 hours instead of 8 or more -- made people three times more likely to get sick after exposure to a cold virus. Now that's something to sleep on.

When Quality Matters
Seems your immune system takes a hit from both lack of sleep and poor sleep. In fact, poor sleep may have an even bigger impact than short sleep. People in the study were five times more likely to get sick when their sleep quality dipped -- even if it just dipped a smidge. Are you tossing and turning at night? Take the RealAge Sleep Quiz to find out why -- and how to fix it.

Deprivation Dampens Immunity
Two important weapons your immune system needs to fight disease: natural killer cells and interleukin-2. But poor sleep impairs them both, so amp these immune-system helpers back up with these sound-slumber strategies:

• Dive deep. Into sleep, that is, with this Deep Sleep Plan from the YOU Docs.
• Step away from the laptop. Find out why surfing the Web just before bed can keep you awake all night.
• Practice good hygiene. Here are the essential sleep-hygiene habits that lead to better sleep.

And avoid these bedtime no-nos if you want a good night's rest.