How It Feels
The blood sample is taken from a vein in
your arm. An elastic band is wrapped around your upper arm. It may feel tight.
You may feel nothing at all from the needle, or you may feel a quick sting or
There is very little chance of a problem from
having blood sample taken from a vein.
- You may get a small bruise at the site. You can
lower the chance of bruising by keeping pressure on the site for several
- In rare cases, the vein may become swollen after the blood
sample is taken. This problem is called phlebitis. A warm compress can be used
several times a day to treat this.
- Ongoing bleeding can be a
problem for people with bleeding disorders. Aspirin, warfarin (Coumadin), and
other blood-thinning medicines can make bleeding more likely. If you have
bleeding or clotting problems, or if you take blood-thinning medicine, tell
your doctor before your blood sample is taken.
A lactic acid test is a blood test that
measures the level of lactic acid made in the body. Most of it is made by
muscle tissue and
red blood cells.
The normal values listed here-called a reference range-are just a guide. These ranges vary from lab to lab, and your lab may have a different range for what’s normal. Your lab report should contain the range your lab uses. Also, your doctor will evaluate your results based on your health and other factors. This means that a value that falls outside the normal values listed here may still be normal for you or your lab.
Results are ready in 1 day.
A high lactic acid value indicates
lactic acidosis, which can be caused by:
- Severe loss of water from the blood (dehydration).
- Blood problems, such as
- Liver disease or liver damage
that prevents the liver from breaking down lactic acid in the
- Conditions such as severe bleeding,
shock, severe infection,
heart failure, blockage of blood flow to the
carbon monoxide poisoning, or
pulmonary embolism that prevent adequate oxygen from
reaching the body's cells.
- Extremely strenuous exercise or extreme
- 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 Glucophage to control their diabetes, especially if they have poor kidney
What Affects the Test
Reasons you may not be able to
have the test or why the results may not be helpful include:
- Taking large doses of the medicine
- Taking medicines, such as isoniazid for tuberculosis
or metformin (Glucophage) for diabetes.
- Using a lot of
acetaminophen (such as Tylenol) or alcohol.
- Exercising prior to
- Clenching a fist while the blood sample is being drawn.
Also, lactic acid levels may be higher if the tourniquet is around your arm for
a long time.