The symptoms of omicron ba2 infection are varied and atypical, with fever, dry cough and malaise being the main manifestations. Omicron is a new strain of coronavirus that is currently prevalent. Infected patients usually have fever, dry cough, and fatigue as the main manifestations, while some patients may have nasal congestion, runny nose, sore throat, loss of smell and taste, conjunctivitis, myalgia, and diarrhea as the main manifestations. Specific symptoms vary according to the condition. 1. Asymptomatic infected patients or mild patients: Most of the patients infected with Omicron are asymptomatic infected patients with no obvious clinical symptoms; or they are mild patients with low-grade fever, mild fatigue, and impairment of the sense of smell and taste, with no manifestation of pneumonia. 2. Ordinary type: patients may have fever, dry cough, malaise and other manifestations. 3. Severe or critical type: Severe patients tend to develop respiratory distress and/or hypoxemia one week after the onset of the disease, and in severe cases, the disease may rapidly progress to acute respiratory distress syndrome, septic shock, uncorrectable metabolic acidosis and coagulation dysfunction, and multi-organ failure. Once suspected symptoms appear, it is important to improve the nucleic acid test as soon as possible and report to the epidemic prevention department in time.