The best thing you can do in this situation is:
That's right. If you have a cold, or what possibly could be the flu, stay home. Send an email to those professors you are going to miss for the day. If you are going to miss a test, go to the doctors and get that note that many professors require for you to bring in to do the retake. In many cases, missing one class won't hurt you academically, and you can always ask for notes from that class you missed. It isn't worth infecting the students in the 20 foot radius from you with the same cold that you are sporting for the day.
And if you don't have health insurance, or live far away from home, you don't have to suffer through. Sometimes, it worth going in to see a doctor. On my campus, and many campuses around the country, there are campus clinics. These are medical clinics that offer students a lower priced medical care. No, these aren't students practicing on you (though they may be understudying). You'll find real doctors, or nurse practitioners, who will help you out. If you don't have a campus clinic nearby or it's after hours, there are always emergency clinics...and in severe cases the ER. You don't need to suffer through!
If you do decide to stick it out, here are some college style tips:
1. Eat healthy!
I know, this seems to be a given, but it's true. The college diet of pizza and cheeseburgers isn't going to make you feel any better. Eat some vegetables, stay away from the grease for a little while. But get some of those healthy foods into your system.
I know, these seem like what old people take...but it is really worth it for college kids. Vitamin C is what is going to help your immune system the most in recovery from any sickness. You can get it from pills, but also fruit juices (OJ is the best!), and some foods. Try to get that vitamin C and keep away a cold all season long.
3. Soup, soup, soup!
Yup, it is true what they say about chicken noodle soup. Having some warm soup when you are sick will help soothe your throat, loosen up mucous in your nasal passages and just help you feel better overall. So, make some Chicken Noodle, curl up in a blanket and rest.
4. Rest is really the best option.
I know personally that when you are sick, you realize that you are going to fall behind. But if you spend your time being sick, or just ignoring the sickness and doing all the things us busy college kids do, then you'll just get sicker. I don't know how many people I know who won't spend a day in bed when they are sick and end up taking their cold onto bronchitis or even pneumonia. You can afford to take a day off and get some major sleep. Your body will thank you for it and you'll feel MUCH better afterwards.
I know, you hear this one too much too. But it's true. Being sick means you excrete more bodily fluids than normal. Mucous is generally made of water and is there to flush toxins and dust out of your body. You may have phlegm as well, which does the same thing for your lungs. If you have the flu, then you may have nausea. If you are feverish, you'll sweat more than usual. Make sure you are drinking more than normal to make up for these losses. And don't just drink water. Your body needs electrolytes. It will be worthwhile to ask a friend or roommate to run to the store and grab you some Gatorade.
If you don't stay properly hydrated, you chance getting sicker. Dehydration is a serious issue and it may send you to the hospital in a much worse condition then you were in. If you are throwing up and can't keep anything down, find a way to take sips in order to stay hydrated. Dehydration is no laughing matter, and has a whole set of issues that could lead to much more serious complications.
If you find yourself sick this season, I hope you get to feeling better soon. Being sick is no fun, and being away from home while sick stinks more. Hang in there!