Influenza, also known as the flu, mainly occurs when the human body is invaded by influenza viruses, resulting in symptoms primarily of coughing, fever, and sore throat. Besides these symptoms, influenza can also present with gastrointestinal symptoms such as nausea, vomiting, abdominal pain, and diarrhea. The body temperature of patients often exceeds 39°C or 40°C. On the other hand, the common cold is mostly caused by rhinoviruses, parainfluenza viruses, EB viruses, or even infections from Haemophilus influenzae, leading to relatively localized lesions. Common symptoms of a cold include nasal congestion, runny nose, sneezing, and sore throat, and it may not include fever. The prognosis of the common cold is generally better than that of influenza, and it is less likely to lead to severe complications.