Mumps is an acute (sudden and short lived) viral illness, mumps usually presents with inflammation of the salivary glands, particularly the parotid glands. A child with mumps often looks like a chipmunk with a full mouth due to the swelling of the child's parotids (salivary glands near the ears). Mumps can also cause inflammation of other tissues, most frequently the covering and substance of the central nervous system (meningoencephalitis), next the pancreas (pancreatitis) and, especially after adolescence, the ovary (oophoritis) and the testis (orchitis). The mature testis is particularly susceptible to damage from mumps which can lead to infertility.
Together with the likes of measles and chickenpox, mumps was once considered one of the inevitable infectious diseases of childhood. Since a mumps vaccine became available in 1967, the incidence of mumps has declined in the U.S., but there are still many underimmunized populations (for example, more blacks than whites have not yet been immunized). The origin of the word mumps is not clear. It may have to do with the English usage, now obsolete, of "mump" to mean a grimace. More probably, mumps comes from a colder climate, Iceland, where mumpa meant to fill the mouth too full.