COVID-19 is a respiratory disease caused by a new form of the coronavirus that was discovered in December 2019. Coronavirus is a family of viruses that causes several human diseases, including the common cold, Middle East respiratory syndrome (MERS), and severe acute respiratory syndrome (SARS). The majority of people who develop COVID-19 either have mild symptoms or no symptoms. Adults over age 65Trusted Source and people with pre-existing medical conditions are at the highest risk of developing severe complications.