COVID-19 is the infectious disease caused by the last coronavirus that was discovered. This new virus and disease was unknown before the outbreak appeared in Wuhan, China in December 2019.Coronaviruses are a large family of viruses that can be pathogenic in humans and animals. Several coronaviruses are known to cause respiratory infections in humans, with manifestations ranging from the common cold to more serious illnesses such as Middle East Respiratory Syndrome (MERS) and Severe Acute Respiratory Syndrome (SARS).The most common symptoms of COVID-19 are fever, fatigue, and a dry cough.Some patients have pain, stuffy nose, runny nose, sore throat, or diarrhea.These symptoms are usually mild and appear gradually.Some people, although infected, have no symptoms and feel well. Most (about 80%) of people recover without needing any special treatment.About one in six people with the disease have more serious symptoms, including dyspnea.Older people and those with other health problems (high blood pressure, heart problems or diabetes) are more likely to have severe symptoms.Anyone with a fever, cough, and difficulty breathing should see a doctor.Amor Abbassi