code/__DEFINES/diseases.dm

DISEASE_SEVERITY_POSITIVE	Diseases that buff, heal, or at least do nothing at all
DISEASE_SEVERITY_NONTHREAT	Diseases that may have annoying effects, but nothing disruptive (sneezing)
DISEASE_SEVERITY_MINOR	Diseases that can annoy in concrete ways (dizziness)
DISEASE_SEVERITY_MEDIUM	Diseases that can do minor harm, or severe annoyance (vomit)
DISEASE_SEVERITY_HARMFUL	Diseases that can do significant harm, or severe disruption (brainrot)
DISEASE_SEVERITY_DANGEROUS	Diseases that can kill or maim if left untreated (flesh eating, blindness)
DISEASE_SEVERITY_BIOHAZARD	Diseases that can quickly kill an unprepared victim (fungal tb, gbs)

Define Details

Diseases that can quickly kill an unprepared victim (fungal tb, gbs)

Diseases that can kill or maim if left untreated (flesh eating, blindness)

Diseases that can do significant harm, or severe disruption (brainrot)

Diseases that can do minor harm, or severe annoyance (vomit)

Diseases that can annoy in concrete ways (dizziness)

Diseases that may have annoying effects, but nothing disruptive (sneezing)

Diseases that buff, heal, or at least do nothing at all