Hypo-

From Wikipedia, the free encyclopedia

Hypo- is a prefix imported from Greek meaning "below", "low", or "insufficient".

In medicine, this prefix occurs in terms denoting an abnormally low level of a certain substance in the body, such as hypocalcaemia (a low level of serum calcium) and hypoglycaemia (a low level of blood sugar). It is also used in the names of conditions involving under-active functions, such as hypothyroidism and hyposplenism.

In anatomy, the prefix is used in its sense of "below", to describe the location of parts of the body; for example, the hypothalamus is a region of the brain below the thalamus.

In chemical nomenclature, the prefix is used in the names of oxoacids and oxyanions with a low amount of oxygen. For example, the hypochlorite ion (ClO⁻) has only one oxygen atom, the least of the four oxyanions of chlorine.

In photography, "hypo" refers to sodium thiosulfate, a fixer used in the final stage of dark room photograph creation. Up until the 1970s, sodium thiosulfate was the most commonly used fixer.

As a word, hypo may refer to:

• a hypoglycaemia attack in a person with diabetes
• the substance sodium hyposulfite
• a hypodermic syringe