The main differences between the common cold and the flu lie in the severity of the illness, the speed of onset, and the general characteristics of the symptoms observed. The flu typically starts more suddenly and runs a more severe course than a common cold. In the flu, systemic symptoms such as high fever, significant headache, widespread muscle and joint aches, chills, and severe fatigue are prominent. A dry cough, sore throat, and nasal congestion may also be present. A common cold, on the other hand, presents with milder symptoms; sneezing, runny nose, nasal congestion, and a mild sore throat are more common. While high fever and widespread body aches are rarely seen in a common cold, these symptoms are quite typical for the flu.