- Chosen by Voters Both are caused by viruses but the symptoms are different. With a cold the symptoms start gradually over a period of a few days. The flu starts quickly, with a high fever developing over a few hours.Cold: Sneezing, runny nose, congestion, tiredness, cough, sore throat sometimes.Flu: Sudden onset of fever, sore throat, muscle aches, exhaustion, some congestion. 5 years ago 100% 1 Vote