Cases of mumps may start with a fever of up to 103 degrees Fahrenheit (39.4 degrees Celsius), as well as a headache and loss of appetite. The well-known hallmark of mumps is swelling and pain in the parotid glands, making the child look like a hamster with food in its cheeks. The glands usually become increasingly swollen and painful over a period of 1 to 3 days. The pain gets worse when the child swallows, talks, chews, or drinks acidic juices (like orange juice).

Both the left and right parotid glands may be affected, with one side swelling a few days before the other, or only one side may swell. In rare cases, mumps will attack other groups of salivary glands instead of the parotids. If this happens, swelling may be noticed under the tongue, under the jaw, or all the way down to the front of the chest.

Mumps can lead to inflammation and swelling of the brain and other organs, although this is not common. Encephalitis (inflammation of the brain) and meningitis (inflammation of the lining of the brain and spinal cord) are both rare complications of mumps. Symptoms appear in the first week after the parotid glands begin to swell and may include: high fever, stiff neck, headache, nausea and vomiting, drowsiness, convulsions, and other signs of brain involvement.

Mumps in adolescent and adult males may also result in the development of orchitis, an inflammation of the testicles. Usually one testicle becomes swollen and painful about 7 to 10 days after the parotids swell. This is accompanied by a high fever, shaking chills, headache, nausea, vomiting, and abdominal pain that can sometimes be mistaken for appendicitis if the right testicle is affected. After 3 to 7 days, testicular pain and swelling subside, usually at about the same time that the fever passes. In some cases, both testicles are involved. Even with involvement of both testicles, sterility is only a rare complication of orchitis.

Additionally, mumps may affect the pancreas or, in females, the ovaries, causing pain and tenderness in parts of the abdomen.

In some cases, signs and symptoms of mumps are so mild that no one suspects a mumps infection. Doctors believe that about one in three people may have a mumps infection without symptom Contagiousness
The mumps virus is contagious and spreads in tiny drops of fluid from the mouth and nose of someone who is infected. It can be passed to others through sneezing, coughing, or even laughing. The virus can also spread to other people through direct contact, such as picking up tissues or using drinking glasses that have been used by the infected person.

People who have mumps are most contagious from 2 days before symptoms begin to 6 days after they end. The virus can also spread from people who are infected but have no symptoms.