Mumps is caused by a virus and is generally described as a mild disease that causes swollen glands on one or both sides of the neck. Some people that are infected never show symptoms at all. Mumps usually occurs during childhood, but adults who have not been vaccinated against mumps may also become infected.
Mumps is spread through saliva and droplets from the nose and mouth.
In other words, it is spread through the air after a person coughs or sneezes, especially if they don't cover their nose or mouth. The first symptoms appear after about 18 days, but can develop anytime between 12 to 25 days after contact with an infected person. Symptoms of mumps disease tend to decrease after 1 week and are usually gone by 10 days. If testicular swelling develops, it usually subsides after 1 week, but tenderness may last for several weeks. One infection of mumps protects a person for the rest of their life.