You’re skimping on sleep:
It may feel like overkill to turn in early just because you have the sniffles. But you’re probably sleep-deprived to begin with, and your body needs adequate rest to fight off infection efficiently. Getting some extra shut-eye might be the tonic you desperately need. (Here are 11 strategies to sleep better tonight.) “Sleep is the body’s way to recharge and rest,” says Caleb Halulko, DC, a chiropractor in Traverse City, MI. “I cannot overstate the importance of restful sleep in helping the immune system function better.” Aim for a full 7 or 8 hours, ideally every night (but especially when you’re sick).
You’re a smoker:
There are plenty of reasons to quit, but here’s one more: Not only do smokers typically have more severe cold symptoms than non-smokers, but smoking can make your cold stick around longer. “Symptoms often linger in those who are smokers,” says Amesh A. Adalja, MD, a board-certified infectious disease physician at the University of Pittsburgh.
The HealthCare Blog 