Lactic acid test

A test for lactic acid is done to:

• Check for lactic acidosis. Symptoms of lactic acidosis include rapid breathing, excessive sweating, cool and clammy skin, sweet-smelling breath, belly pain, nausea or vomiting, confusion, and coma.
• See whether the right amount of oxygen is reaching the body's tissues.
• Find the cause for a high amount of acid (low pH) in the blood.

A health professional uses a needle to take a blood sample, usually from the arm.

To prepare for a lactic acid test:

• Do not eat or drink anything other than water for 8 to 10 hours before the test.
• Do not exercise for several hours before the test. Do not clench your fist while having your blood drawn for a lactic acid test. These activities may change the results.

Normal

Each lab has a different range for what's normal. Your lab report should show the range that your lab uses for each test. The normal range is just a guide. Your doctor will also look at your results based on your age, health, and other factors. A value that isn't in the normal range may still be normal for you.

High values

A high lactic acid value means lactic acidosis, which can be caused by:

• Severe loss of water from the blood (dehydration).
• Blood problems, such as severe anemia or leukemia.
• Liver disease or liver damage that prevents the liver from breaking down lactic acid in the blood.
• Conditions such as severe bleeding, shock, severe infection, heart failure, blockage of blood flow to the intestines, carbon monoxide poisoning, or pulmonary embolism that prevent adequate oxygen from reaching the body's cells.
• Extremely strenuous exercise or extreme overheating.
• Poisoning by alcohol (ethanol), wood alcohol (methanol), or antifreeze (ethylene glycol).
• Some medicines, such as isoniazid for tuberculosis or metformin (Glucophage) for diabetes. Lactic acidosis is a concern for people who take metformin to control their diabetes, especially if they have poor kidney function.