Severe acute respiratory syndrome (SARS) is a respiratory illness caused by a type of virus called a coronavirus. SARS produces symptoms similar to pneumonia and can be spread when someone with SARS coughs, sneezes, laughs, or speaks.

The main symptoms are a fever, a dry cough, shortness of breath, or difficulty breathing. Some people also have a headache, muscle aches, a sore throat, fatigue, and diarrhea. Symptoms usually appear 2 to 5 days after a person becomes infected but they may not appear until 10 days later.

Research is ongoing to find effective treatment for SARS. Mild cases may be treated at home, like the flu or a cold. Severe cases require a hospital stay to treat breathing problems. SARS can be fatal. The risk of dying from SARS varies depending on a person's age and health, with the greatest risk to people older than 65 and those who have chronic illnesses such as diabetes and heart disease. Several antiviral medicines are being studied to treat SARS.