Both the flu and the common cold are respiratory illnesses but caused by different pathogens. These two types of illnesses have symptoms that are similar to flu. Therefore it is difficult to differentiate between them just by looking at the symptoms alone.
The flu illness is worse than the common cold with the symptoms such as fever, body aches, extreme tiredness, headache, congestion and cough.
The common cold is milder than the flu with the symptoms of sore throat, runny or stuffy nose. Fever is uncommon in adults, but children can develop fever with cold. With the cold, patients do not get serious health issues such as pneumonia, bacterial infections, or hospitalizations.
Most of the times, the common cold symptoms can make people feel sick for a few days, but flu symptoms can make people quite ill for a few days to weeks. The flu can also result in serious health problems including pneumonia and hospitalizations.