So what's the difference between cold and flu. The two words go together like salt and pepper or like New Year's and weight loss. I'm Dr. Alan Greene and I want to help you figure out what the difference is. Most people have a general idea that they are different, but when pressed have a hard time really saying what the difference is. The cold, the common cold, is something very common you usually get on average 3 or more times during a year. And it is a virus that's primarily in the nose. The cold is focused in the nose. The 3 main symptoms of a cold are sneezing, nasal stuffiness, and runny nose. All are focused in the nose. You may have other symptoms - you may have a fever of 100°, 101°, maybe you may have some tickling or scratchiness in the back of the throat. In fact, that may be the very first symptom - a little scratch in the back of the throat. Then after a couple days the nasal discharge tends to turn a little bit darker, greener. And then after about a week you're all the way better. But it's focused in the head, focused in the nose.

With the flu you're sick all over. It's a whole body disease. It's a much more serious illness. The flu in the United States today still kills about 36,000 people a year. Mostly people who already are weak for some reason or another. But it's a serious illness. And it usually slams into you with a fever. Typically the fever is in the 102° all the way up to a 106° range. A higher fever often the first symptom and you feel sick all over. You have muscle aches, you're tired, you feel out of it, you really feel crummy. And after a couple of days the respiratory symptoms start to come too. And depending where the flu virus settles you might have some sneezing, you might have some coughing. The classic symptom is a dry, hacking kind of cough, could be wheezing, could be other things, but the cough is the most common. Then it's there also for around 7 days or so and then at the end of it you may have another peak of fatigue and a second peak of fever. But usually after about a week you'll start feeling better with most cases of the flu.

Colds and flus are very, very different illnesses with a few of the same symptoms.