Colds and the flu have so much in common that it can sometimes be hard to tell them apart. Both are caused by viruses that infect your airways. They have some of the same symptoms that can leave you feeling miserable.
There are enough differences, though, that may help you figure out which one you have. That can make a difference in what you do to treat your symptoms and keep it from going around.
Symptoms
It’s true that you can get a cold anytime -- spring, summer or fall, but most likely in winter. Flu season typically runs from November through March, although you can get the flu in October or as late as May.
You can catch the flu at other times. But symptoms outside of flu season are more likely to be from a cold or an allergy.
Flu symptoms usually come on faster than cold symptoms. Colds may take two or three days to develop. Normally, you start feeling the flu over just two to three hours.
Flu tends to be much worse than a cold. And the flu, especially in children and among older people, is more likely to lead to serious health problems such as pneumonia and a hospital stay.
|
Symptom |
Cold |
Flu |
|
Fever |
Rare |
Fever between 100 and 102 in most cases; typically lasts 3-4 days |
|
Chills |
Not common |
About half of people with flu get them. |
|
Muscle or body aches |
Not common. If they do occur, usually mild |
Common and often severe |
|
Headaches |
Not common |
Most cases; may be sudden |
|
Feelings of fatigue, weakness |
May occur, generally mild |
Moderate to severe fatigue and weakness; may last up to 2-3 weeks |
|
Cough |
Common, generally mild to moderate, usually produces phlegm |
Dry cough (no phlegm) that may be severe; may last several weeks |
|
Sneezing and stuffy nose |
Common. Stuffy nose may last about a week. |
Sometimes |
|
Sore throat |
Common |
Sometimes |
|
Chest discomfort |
Sometimes; generally mild |
Common; may be severe |
|
Vomiting and diarrhea |
Unusual |
Not usual; most often in children |
Rarely, symptoms may not be enough for your doctor to know it's a cold or the flu. Then your doctor may order a test to determine what you have.

