Mumps causes fever, headache and swelling of the salivary glands which makes your cheeks look swollen. However, about one third of people who catch mumps do not have salivary gland swelling. About one out of every four men with mumps develops painful swelling of the testicles. One out of every 20 women develops swelling of the ovaries. Both of these conditions are temporary and rarely result in permanent damage or sterility.
Mumps can also cause temporary deafness due to fluid in the middle ear.
Permanent deafness occurs in less than 5 cases out of 100,000 cases of mumps. This usually goes away without causing permanent damage. Encephalitis occurs in about 1 or 2 cases out of 10,000 cases of mumps. These complications of mumps infection can occur at any age but are more likely to occur in teens and adults than in children. Mumps infection during the early stage of pregnancy may increase the rate of miscarriage, but mumps does not appear to cause any abnormality in the unborn baby.