At first, the flu may seem like a cold with a runny nose, sneezing and sore throat. Colds usually start slowly. But the flu tends to come on quickly. And while a cold can be miserable, you usually feel much worse with the flu. Common symptoms of the flu often — but not always — include a fever as well as aching muscles, chills and sweats. Other symptoms include: Headache. Dry, persistent cough. Shortness of breath. Tiredness and weakness. Runny or stuffy nose. Sore throat. Eye pain.