Severe acute respiratory syndrome (SARS) is a disease caused by human infection with SARS-CoV, and its incubation period is usually within 2 weeks, about 2-10 days. SARS is mostly acute in onset, and most patients have fever as the first and main symptom, with temperature usually ≥38°C and persistent high fever, accompanied by chills, muscle and joint aches, headache, and weakness. Cough is not uncommon and mainly presents as a dry cough with little sputum, and a few patients may have a sore throat. Patients may develop symptoms such as chest tightness, and in severe cases may gradually develop accelerated breathing, shortness of breath, or even respiratory distress. Patients usually have no upper respiratory cicatricial symptoms. Respiratory distress and hypoxemia are most often seen 6-12 days after the onset of the disease. Some patients may develop gastrointestinal symptoms such as diarrhea, nausea and vomiting.