Consumer Reports: Is it a cold or the flu?

While the flu season is well underway, the CDC says it's still not too late to get vaccinated. But there are medicines to treat the flu if you do get it. But how do you really know if you have it or just a nasty cold? Consumer Reports breaks down the differences. There's one telltale sign to look out for.

Nasty colds are never fun, but the flu can be much more serious. So how do you tell the difference? Consumer Reports says there's one sure thing to look for-the flu hits you like a ton of bricks. It can come on in a few hours.

AND you'll likely have these added symptoms: feeling feverish or having a fever, chills, muscle aches, and extreme tiredness. A cold has similar but milder symptoms: a runny or stuffy nose, cough, sore throat, fatigue.

With the flu, you want to go to bed. You just feel like you can't move.

So what should you do if you suspect you have the flu? Consumer Reports says you may want to call your doctor to see whether you're a candidate for antiviral medicine, like Tamiflu or the new one on the market, Xofluza. Both work best if taken within 24 to 48 hours of getting symptoms and may shorten the duration of the flu by one or two days. Xofluza requires only one dose; Tamiflu requires you take it twice a day for five days.

Keep in mind that both flu medicines are expensive. With a coupon, Tamiflu will cost you about $50 and Xofluza will run about $30 based on what your insurance company covers.

And if you do have the flu? Do everyone a favor and call in sick.