hypo-, hyp-

(Greek: under, below, beneath; less than; too little; deficient, diminished; used as a prefix)

hypoventilation
1. Abnormally slow and shallow respiration, resulting in an increased level of carbon dioxide in the blood.
2. A condition in which there is a reduced amount of air entering the pulmonary (lung) alveoli (small cell containing air in the lungs), resulting in decreased levels of oxygen and increased levels of carbon dioxide in the blood.

Hypoventilation can be a result of breathing that is too shallow (hypopnea) or too slow (bradypnea) or to diminished lung function.

hypovitaminosis, paravitaminosis, vitanition
1. A physical disorder resulting from nonspecific vitamin deficiency.
2. A condition due to a deficiency of one or more essential vitamins.
hypoxemia
hypoxia
1. A condition characterized by abnormally low levels of oxygen in the blood and tissues.
2. In ecology, a condition in which inadequate environmental oxygen is available to an organism.

The "Dead Zone" off the Louisiana coast mapped during the last week of July, 2006, is reported to be 6,662 square miles; or about the size of Connecticut and Rhode Island combined, Dr. Nancy Rabalais, Chief Scientist for Northern Gulf of Mexico Hypoxia Studies reported on Friday. The low oxygen waters extended from near the Mississippi River to the Louisiana-Texas border.

Agricultural runoff in the vast area drained by the Mississippi River contributes most of the nitrogen, phosphorus and other nutrients that feed a population boom of algae. As the algae die, they fall to the bottom. Their decay consumes oxygen faster than currents can bring it down from the surface.

—Published July 29, 2006, in Space and Earth;
" 'Dead Zone' off La. coast gets larger"
hypoxyphilia
In psychiatry, the same as asphyxiophilia; a sexual perversion in which hypoxia [an abnormal condition resulting from a decrease in the oxygen supplied to body tissue] and the altered state of consciousness it produces is an essential part of sexual arousal.

Hypoxia may be induced by drugs or by strangling or hanging; some classify such autoerotic asphyxiation as a form of sexual masochism.

hypozoic
Anterior (in front of) in age to the lowest rocks which contain organic remains.
iliohypogastric
panhypopituitarism (s) (noun), panhypopituitarisms (pl)
A defective or absent function of the entire pituitary gland which is a small, gray, rounded gland that regulates many bodily processes including growth, reproduction, and various metabolic activities: If there is any decreased secretion of most or all of the pituitary hormones, the term panhypopituitarism is used.
photohyponasty, photohyponastic, photohyponastically
1. Excessive growth caused by the action of light.
2. Hyponasty which is the result of exposure to intense light following an arrest of growth.
planktohyponeuston
1. Organisms that accumulate near the surface of water at night but live at lower levels during the day.
2. Aquatic organisms which gather near the surface at night but spend their days in the main water mass.
tactile hypoesthesia (s) (noun), tactile hypoesthesias (pl)
A reduced perception of touch: Mindy was experiencing tactile hypoesthesia or numbness in her feet after the operation on her cracked vertebrae.
thermhypesthesia, thermohypesthesia, thermohypoesthesia (s) (noun); thermhypesthesias, thermohypesthesias, thermohypoesthesias (pl)
Diminished sensitivity to hot or cold stimuli: As a result of his thermhypesthesia, Clarence was able to hike for miles on a cold day and still be comfortable.

Hans was sweating less than usual when he was climbing up the mountain which suggested that he was experiencing thermhypesthesia.

thermohypesthesia, thermohypaesthesia (s) (noun); thermohypesthesias, thermohypaesthesias (pl)
Diminished sensibility to heat stimuli including high temperatures: Clare had to be constantly on guard about what she was touching; especially, when she was cooking because her thermohypesthesia didn't let her know when something was dangerously hot.
thermohypoesthesia (s) (noun), thermohypoesthesias (pl)
A lack of sensibility to heat stimuli: Mr. Johnson’s hands had thick calluses on them as a result of his working on the railroads which caused thermohypoesthesia or being unaware of anything being very hot whenever he happened to touch any excessively hot objects.
vasohypotonic
Relating to reduced arteriolar (smallest divisions of the arteries) tension or vasodilation (increase in the internal diameter of a blood vesse).