What does the prefix hypo- mean?

• A. Not
• B. Below
• C. Excessive
• D. Deficient

Answer: (D)

Hypo- signals a state of being lower than normal or lacking in amount or function. In medical terms, it’s used to describe a deficiency, so the best fit is “deficient” because hypo- conveys not having enough of something (deficient glucose in hypoglycemia, deficient oxygen in hypoxia, etc.). While it can imply “below” in a general sense, the clinical meaning students focus on is deficiency. The other options don’t capture that deficiency sense: “not” isn’t the standard prefix, “below” is a directional cue but doesn’t directly express the insufficiency, and “excessive” is the opposite concept (hyper-).