Colds can usually be recovered in 5 to 7 days without medication, but there may be comorbidities or coughing symptoms that can lead to prolonged illness. Colds are usually caused by viral infections, and the main clinical features are runny nose, sneezing, coughing, low-grade fever and manifestations such as fatigue and muscle aches. The disease is usually self-limiting, relying on its own immunity for 5 to 7 days may recover. However, some colds may have comorbidities, such as bacterial upper respiratory tract infections or bacterial pneumonia, in which case the illness may be prolonged. In some cases, although the infection is under control, there may be a prolonged cough, which can last up to 1-2 months and is called post-infectious cough. To summarize, patients with colds also need to pay attention to the observation of the condition, once the clinical symptoms persist for a long time without improvement, need to consult a doctor in time to adjust the program.