Colds can be broadly categorized into three stages: early stage, middle stage and recovery stage, with different symptoms. 1. Early stage: It is mainly caused by inflammatory symptoms, patients will have different degrees of nasal congestion, runny nose, throat discomfort and other clinical manifestations. 2. Intermediate stage: also known as the infection stage, this stage is mainly caused by viral invasion. Patients will have symptoms such as congestion and swelling of the mucous membrane of the throat, sore throat, hoarseness, cough, dizziness and headache, etc. Some patients may also have gastrointestinal reactions such as loss of appetite, bloating, diarrhea and constipation, and in severe cases, fever may occur. 3. Recovery phase: The patient’s mental temperature will gradually return to normal and appetite will gradually increase, but some patients may still have mild flu symptoms such as nasal congestion and runny nose. In the case of influenza, there is still an incubation period. Severe influenza can easily be combined with pneumonia or other organ function involvement, which requires high attention. Colds should also be aware of the possibility of secondary bacterial infections, such as sinusitis, otitis media, or pneumonia, when the 3 phases do not apply, and it is recommended that patients actively seek medical attention when a cold occurs and be treated under a doctor’s supervision.