Hypoxia: low oxygen levels in the blood Hypovolemia: low amount of circulating blood, either absolutely due to blood loss or relatively due to vasodilation Hyperkalemia or hypokalemia: disturbances in the level of potassium in the blood, and related disturbances of calcium or magnesium levels. Hypothermia/Hyperthermia: body temperature not maintained Hydrogen ions (Acidosis) Hypoglycemia: Low blood glucose levels