Medical Definition of HPI. history of present illness.What made you want to look up HPI? Please tell us where you read or heard it (including the quote, if possible). View Seen & Heard Highlights from Around the Site. Test Your Vocabulary! Test Your Vocabulary!10 Charming Words for Nasty People.edical Definition of HPI. history of present illness.
parÂ·aÂ·sitÂ·oid. n. An organism, usually an insect, that lives on or in a host organism during some period of its development and eventually kills its host. parâ²aÂ·sitÂ·oidâ² adj.
A parasite is an organism that lives on or in a host organism and gets its food from or at the expense of its host. There are three main classes of parasites that can cause disease in humans: protozoa, helminths, and ectoparasites.rotozoa. Protozoa are microscopic, one-celled organisms that can be free-living or parasitic in nature. They are able to multiply in humans, which contributes to their survival and also permits serious infections to develop from just a single organism.