An<unk>  is the detrimental colonization of a host organism by a foreign species.  In an<unk> , the<unk> g organism seeks to utilize the host's resources to multiply (usually at the expense of the host). The<unk> g organism, or pathogen, interferes with the normal functioning of the host and can lead to chronic wounds, gangrene, loss of an<unk> ected limb, and even death. The host's response to<unk>  is<unk> lammation.  Colloquially, a pathogen is usually considered a<unk> croscopic organism though the definition is broader, including feces, parasites, fungi, viruses, prions, and viroids.  A symbiosis between parasite and host, whereby the relationship is beneficial for the former but detrimental to the latter, is characterised as parasitism.  The branch of medicine that focuses on<unk> s and pathogens is<unk> s disease.
A secondary<unk>  is an<unk>  that occurs during or following treatment of another already existing primary<unk> .
Infection
Disease
Neurotoxicity
Neoplasia
Congenital abnormality
Infectious disease
Bacterial disease
Electrical injury