-asis Also -iasis.
A disease or other medical condition.
[Via Latin from Greek -asis.]
The most common examples are words describing diseases caused by an external parasite, frequently tropical or subtropical in origin. Despite its origin, which determines its place in this work, the ending is almost always -iasis, incorporating the linking vowel -i-.
Examples are candidiasis, infection with candida, a yeast-like parasitic fungus, especially when it causes oral or vaginal thrush; leishmaniasis, a tropical and subtropical disease caused by a parasitic protozoan (named after William Leishman, 1856-1926, a British pathologist); schistosomiasis, now more commonly called bilharzia or bilharziasis, a chronic disease caused by infestation with blood flukes; and elephantiasis, a condition in which a limb or other part of the body becomes grossly enlarged due to obstruction of the lymphatic vessels, typically by the filarial worms which also cause filariasis.
A variety of other medical conditions contain this ending: lithiasis (Greek lithos, stone), formation of stony concretions, specifically urolithiasis, in the bladder or urinary tract, and cholelithiasis, gallstones; psoriasis, a skin disease marked by red, itchy, scaly patches (Greek psōra, itch); hypochondriasis is the technical term for hypochondria.