Mumps is an illness caused by the mumps virus. It starts with
Fever
Headache
Muscle aches
Tiredness
Loss of appetite
After that, the salivary glands under the ears or jaw become swollen and tender. The swelling can be on one or both sides of the face. Symptoms last 7 to 10 days. Serious complications are rare.
You can catch mumps by being with another person who has it. There is no treatment for mumps, but the measles-mumps-rubella (MMR) vaccine can prevent it.
Before the routine vaccination program in the United States, mumps was a common illness in infants, children and young adults. Now it is a rare disease in the U.S.
Centers for Disease Control and Prevention