What are the tests that will detect lactic acidosis?

Lactic acidosis is a rare side effect of metformin. However, the risk of lactic acidosis increases in patients with poor kidney function. Your doctor should regularly monitor your kidney function while you are on metformin. Blood tests to measure your electrolyte levels can determine if you have lactic acidosis. Typically your doctor will evaluate your blood work 1 to 2 weeks after you begin taking metformin to make sure you electrolytes are within normal limits. You can also monitor for symptoms of lactic acidosis which include abdominal or stomach discomfort; decreased appetite; diarrhea; fast, shallow breathing; general feeling of discomfort; muscle pain or cramping; and unusual sleepiness, tiredness, or weakness. If symptoms of lactic acidosis occur, you should get immediate emergency medical help.

With lactic acidosis, lactic acid builds accumulates in the blood stream faster than it can be removed. This can be caused by extended, intense exercise or other certain diseases, and is marked by nausea and weakness. Blood tests that check electrolyte levels are used to detect lactic acidosis.