Mumps is a contagious viral infection spread by droplet infection. This typically causes enlargement of one or more of the salivary glands. These glands are located on either side of the face, below the ears.

This gives an appearance rather like a "hamster with food in it's cheeks"

Etiology and Incidence: This is less communicable than measles or chickenpox. One attack usually confers permanent immunity, even though only one salivary gland has been enlarged. About 25 to 30% of cases are clinically in apparent.