3.Flu: Fatigue Can Last for Weeks
You likely start off feeling extremely tired and achy all over. That fatigue and weakness may last for up to 3 weeks — or even longer in seniors and people with long-term (chronic) diseases or a weak immune system. With a cold, you usually feel bad for just a few days.
4.Colds and Flu: Both Can Cause Headaches
Still, a headache that comes along with a cold, like other symptoms that result from the virus, tends to be milder than one caused by flu.
