Why does mumps cause fever?

Mumps is a viral infection that often affects the salivary glands near the jaw and ears. The immune response can release signals that make the brain hold the body at a higher temperature for a time. Fever is a very common presentation of Mumps; it may come with tiredness, headache, muscle aches, loss of appetite, or swelling and tenderness around one or both sides of the face. Fever has many possible causes, so it does not on its own establish mumps.

Rest, take regular fluids, and choose soft foods if chewing is uncomfortable. A cool compress on the swollen area may ease discomfort. Use pain or fever relief only according to the label or advice from a clinician, especially for children or people with ongoing health conditions. Contact a healthcare professional for confirmation and local advice. Avoid close contact, kissing, and sharing cups, cutlery, towels, or toothbrushes while you are unwell, because respiratory droplets and saliva can pass the virus on.

Get urgent medical help for severe headache, stiff neck, confusion, repeated vomiting, trouble breathing, severe dehydration, or sudden severe testicular pain or swelling. Seek same-day clinical advice if facial swelling is worsening, fever is accompanied by a widespread rash, or you are pregnant, immunocompromised, or caring for a very young child. A clinician can also assess other causes of facial swelling and fever.

Ask whether the illness is likely to be mumps, whether testing is needed, and when it is appropriate to return to work, school, or close-contact activities. Tell the clinician about vaccination history, the side of facial swelling, ear pain, testicular symptoms, pregnancy, and anyone at home who may be vulnerable to infection.