"Everybody can react to these medicines differently. For some, they can bring on sleepiness, but others may find it makes them feel jittery and nervous and actually keep them from falling asleep or staying asleep," Nicholas Popovich, Ph.D., professor of pharmacy administration and department head at the University of Chicago at Illinois College of Pharmacy, tells Medicine Net.

Medications containing pseudoephedrine can cause this jittery effect. This ingredient is often found in cough and cold medications.

Popovich advises those with colds to beware of medications containing diphenhydramine. This ingredient, found in Benadryl and other cold relief medication, may make some sleepy but have the opposite effect on others.

There’s a general rule of thumb when it comes to medications containing these ingredients. "Until you know how you personally react, it's best to avoid them after 6 p.m., particularly if you have to be at work the next day," Popovich says.

So what do you do if you’re all stuffed up? One option is a common nasal decongestant spray. "The effects are mostly localized, so you're less likely to get that jittery feeling," Popovich told Medicine Net.

And if these sprays bother you, try a saline nasal spray, which will irrigate the nose, clearing it of impurities and making it somewhat easier to breathe.

Drink a lot of water.

There’s a reason doctors and nurses say to drink fluids when you’re sick. Water flushes out toxins in the system -- and it can help to clear out nasal drainage in the throat. Hot liquids can help, too. These are known to help with sickness.