It’s that time of year: sniffles, sneezes, the cough that annoys you (and your co-workers even more). You feel it coming on about a week before, but you continue faithfully plugging away at your work. And why not? A professional isn’t sidelined by something as insignificant as a lack of energy or a cough, right?

But then, the week passes—and you . . . feel . . . LOUSY. You’re full-blown sick, and you have to either stay home and rest (and hope nothing catastrophic happens in your absence), or you bite the bullet and go into work sick as a dog. Which everyone in your office really appreciates, I’m sure.

But it doesn’t have to be this way.

Are you making sure to eat breakfast every morning? Keeping your blood sugar at normal levels, especially in the morning, can boost your immune system and keep you from feeling run-down before lunch. It’s good for weight loss, too.

Are you getting your eight hours of sleep every night? Yes, it is humanly possible even for business professionals to get a good night’s sleep each night. If you need motivation to make it a priority, consider this: when you don’t get enough sleep, your immune system daily becomes weaker and weaker. Eventually, the nasty little cold and fever bugs win the battle—sending your fever up, and leaving you bedridden for the next day or two.

Stress levels can be a factor, too, along with several other things. In fact, why don’t you brush up on exactly what it is you may be doing to make yourself sick (albeit unintentionally) by reading this article that Yahoo! recently published?

. . . and keep your nose clean.