Medical Daily – Seerat Chabba 
While both are respiratory illnesses, the flu and the common cold differ in the matter of severity — both caused by different viruses. It is difficult to differentiate between the two as the symptoms can be very similar in most cases. However, the intensity of the symptoms differs in both cases, with the flu being much worse than the common cold — which is usually milder. A runny or stuffy nose is more closely associated with the colds and do not usually end in more serious health problems. Bacterial infections or hospitalizations with the common cold are rare but the flu can have very serious complications associated with it.(more)