Cold and flu symptoms are similar but flu tends to be more severe. Colds cause more nasal problems than flu. Fever, fatigue and muscle aches are more likely and more severe with flu.
A cold develops gradually over one or two days and you’re most contagious during the early stages when you have a runny nose and sore throat. You should begin to feel better after a few days but some colds can last up to two weeks.
Flu usually comes on much more quickly than a cold, and symptoms appear one to three days after infection. You should begin to feel better within a week or so, but you may feel tired for much longer.