Most people do not have a clear concept of “cold”, and even some medical professionals do. They diagnose it as “upper respiratory tract infection” regardless of whether it is a viral or bacterial infection, a cold or flu, or an upper or lower respiratory tract infection. In fact, the concepts of cold, influenza and upper influenza are different, and the clinical treatment and prevention methods are also different. Both colds and flu are caused by viral infection of the respiratory tract, but the most important difference between them is that colds do not cause epidemics and are sporadic. The term “upper respiratory tract infection” refers to infections of the upper respiratory tract above the cricoid cartilage at the laryngeal junction and can be caused by either bacteria or viruses. Cold: including the common cold and influenza. Common cold is commonly known as “cold”, also known as upper sensation, acute nasopharyngitis, acute pharyngitis, acute tonsillitis, etc., with nasopharyngeal cartilage symptoms as the main manifestation. There are more than 200 kinds of pathogens, mainly viruses and bacteria, such as rhinovirus, coronavirus and parainfluenza virus, etc. It is a mild, self-limiting common disease of the upper respiratory tract. Although the common cold occurs mostly in early winter, it can occur in any season, such as spring and summer, and the viruses that cause the cold are not exactly the same in different seasons. The distribution of cold cases is sporadic, does not cause epidemics, and is often easily combined with bacterial infections. Cold is a common clinical disease with high morbidity. It can occur throughout the year, with winter and spring being the most common. It is sporadic and may occasionally cause epidemics. It can occur at any age, with the highest incidence in children. Therefore, the common cold, influenza, bacterial purulent tonsillitis, and even acute bacterial bronchitis caused by cold or influenza are all considered as “upper influenza”, and it is inappropriate to use antibiotics and write large prescriptions, which can easily lead to the production of drug-resistant strains of bacteria, and once encountered with moderate to severe bacterial infections, antibiotic treatment is not effective.