Mumps is a contagious illness caused by a virus that infects the salivary glands, especially the parotid glands (between the ear and the jaw), and that sometimes infects other glands, particularly the testicles. The glands become swollen and tender as a result of the infection.

Other symptoms include belly pain and flu-like problems. Mumps can affect people of all ages. In adults, symptoms may be more severe, and complications are more likely. Most people get better with rest and home care. But some people need treatment in the hospital.

Although mumps is not common, it can spread to people who have not received the mumps vaccine (measles, mumps, and rubella series).