| Term | Definition |
| HYPER | over, above, beyond the ordinary |
| HYPO | under, beneath, less than the ordinary |
| Hyperacidity | excessive acidity |
| Hypoglycemia | abnormally low level of sugar in the blood |
| Hypertension | abnormally high blood pressure |
| Hypotension | low blood pressure |
| Hyperthermia | especially high fever |
| Hypothermia | subnormal body temperature |
| Hyperbole | exaggerated statements or claims not meant to be taken literally |
| Hypersensitive | excessively sensitive; supersensitive |
| Hypertrophy | enlargement of a body part or organ, as from excessive use |
| Hypodermic | injected on the skin |
| Hypothetical | assumed without proof for the purpose of reasoning; an opinion or conclusion formed on the basis of incomplete information |
| ENDO | within |
| EXO | out of, outside |
| Endogamy | marriage within the tribe, caste, or social group |
| Exogamy | marriage outside the tribe, caste, or social group |
| Endogenous | produced from within; due to internal causes |
| Exogenous | produced from without; due to external causes |
| Endoskeleton | internal skeleton or supporting framework in an animal |
| Exoskeleton | hard protective structure developed outside the body, as the shell of a lobster |
| Endoparasite | parasite living in the internal organs of an animal |
| Exoteric | external; exterior; readily understandable |
| Exotic | introduced from a foreign country; not native; excitingly strange |