The presence of cold without symptoms generally refers mainly to the absence of typical cata-like symptoms of upper respiratory tract infection, such as patients do not have cata-like symptoms such as nasal congestion, runny nose, sneezing, sore throat, foreign body sensation, and coughing and coughing. However, the patient may have systemic symptoms such as fatigue, loss of appetite, dizziness, headache, and non-catastrophic local symptoms such as depression and aching limbs. The most common clinical condition at this time is a severe cold, such as that caused by the influenza virus, which is characterized by the absence of local symptoms, while the systemic non-cata-like symptoms are more pronounced and can be treated early with antiviral drugs such as oseltamivir.