What causes a high anion gap and low bicarbonate (sodium bicarbonate)?

Metabolic Acidosis: In medicine, metabolic acidosis is a condition that occurs when the body produces too much acid or when the kidneys are not removing enough acid from the body. If unchecked, metabolic acidosis leads to acidemia, i.e., blood ph is low (less than 7.35) due to increased production of hydrogen by the body or the inability of the body to form bicarbonate (sodium bicarbonate) (hco3-) in the kidney.