Illness

Illness is a disease, a serious illness that usually lasts a long time, often one that affects a particular part of the body: tropical diseases. Infection an illness that is caused by bacteria and that does not usually last a long time. Virus a very small germ that causes illness, or an illness caused by these things: The virus is highly contagious. A condition an illness or medical problem that affects someone for a long time. A disorder (formal) a situation in which a particular part of someone’s body does not operate normally, often causing illness for a long period of time. An ailment a minor illness that may be painful or uncomfortable. A bug (informal) an illness caused by a virus or bacteria that is not serious and that does not usually last a long time.