hyper-/hypo-
hyper-/hypo- mean above or below normal (Greek).
"HIGH-per / HIGH-poh." Coach: "Hyper goes high; hypo goes low."
Examples: hypertension, hypotension, hyperglycemia, hypoglycemia, hyperkalemia.
Also: hypokalemia, hypernatremia, hyponatremia, hyperthermia, hypothermia, hyperthyroidism, hypothyroidism.