Is it a cold, or the flu?

Is it a cold or the flu? While the common cold can be caused by over 200 different viruses, seasonal flu is caused by either influenza A or B. Cold symptoms usually begin with a sore throat, followed by nasal congestion and runny nose. A cough may follow on the fourth or fifth day. Fever is uncommon in adults, but a slight fever is possible. Flu symptoms include sore throat, fever, headache, muscle aches and soreness, congestion, and cough. Symptoms are similar to the common cold except more severe. A common complication of the flu is pneumonia and it is not uncommon to feel run down for over a week when you have the flu.