But, a cold usually doesn't cause a fever - the flu does. Also, a cold causes a stuffy nose more often than flu does. Overall, cold symptoms are milder and don't last as long as the flu. The flu spreads quickly from one person to another. Symptoms Flu symptoms can differ from person to person.
Some people have no obvious symptoms.
Often, however, people with the flu feel weak, develop a cough, a headache, and a sudden rise in temperature. The fever can last from 1 to 6 days. Other symptoms include aching muscles, chills, and red, watery eyes. The flu is rarely fatal. But while your body is busy fighting off the flu, you may be less able to resist a second infection.