Cold or Flu?
Colds and flu are both highly contagious and, in the initial stages, a bad cold and a mild case of the flu might seem alike. Unlike a cold, though, the flu is a serious illness that can have life-threatening complications. Here is a comparison of cold and flu symptoms.
Fever
- With a cold – Fever is rare in adults and older children, but babies and small children may have a fever as high as 102 degrees Fahrenheit.
- With the flu – Fever is often a symptom of the flu and is usually around 102 degrees Fahrenheit, but can go as high as 104 degrees. Fever with the flu usually lasts three to four days.
Headache
- With a cold – Headaches are rare.
- With the flu – Headaches are common, can come on suddenly and may be rather severe.
Muscle aches
- With a cold – Muscle aches are usually mild.
- With the flu – Muscle aches are common and often severe.
Feeling tired and weak
- With a cold – You may be tired and weak, but this feeling is typically mild and never turns into extreme exhaustion.
- With the flu – It's extremely common to feel tired and weak for two weeks or longer. You may also have extreme exhaustion that comes on suddenly.
Runny nose, sore throat and sneezing
- With a cold – It's common to have a runny nose, a sore throat and sneezing.
- With the flu – You may have a runny nose, a sore throat and sneezing.
Cough
- With a cold – A mild hacking cough is common.
- With the flu – Coughing is common and can become severe.
This information was adapted from the U.S. Centers for Disease Control and Prevention (CDC) website. For more information, visit the CDC's flu page.
UCSF Health medical specialists have reviewed this information. It is for educational purposes only and is not intended to replace the advice of your doctor or other health care provider. We encourage you to discuss any questions or concerns you may have with your provider.
