Diseases are caused by the body being overwhelmed by [[toxic]] substances beyond its ability to eliminate them in a normal way. Toxic materials may accumulate from unexpelled body wastes that are generated as a part of [[metabolism]] or from external materials that are ingested and retained due to the body's inability to eliminate them. Disease also refers to [[bacteria]]l and [[viral]] infections of the body. | Diseases are caused by the body being overwhelmed by [[toxic]] substances beyond its ability to eliminate them in a normal way. Toxic materials may accumulate from unexpelled body wastes that are generated as a part of [[metabolism]] or from external materials that are ingested and retained due to the body's inability to eliminate them. Disease also refers to [[bacteria]]l and [[viral]] infections of the body. |