A cold and the flu (also called influenza) are alike in many ways. Both cold and flu can sometimes lead to more serious problems like pneumonia. Cold symptoms are usually a stuffy nose, sore throat, and sneezing. They last a couple of days to a week. Flu symptoms are usually tiredness, fever, headache, and muscle aches and pains. Coughing can be a sign of either a cold or the flu.
You should call your doctor in these situations:
Source: the U.S. Food and Drug Administration