Does this test have other names?
Salicylate serum test, serum salicylate level test, serum salicylate concentration
What is this test?
This is a blood test to check for salicylate intoxication, which is usually caused
by an overdose of aspirin. This test is also used to check for the correct aspirin
dose in people who are given high doses of aspirin to treat inflammation from arthritis.
Aspirin contains acetylsalicylic acid (ASA). Other salicylates are found in some wart
removers, medicines for diarrhea, medicines for bloating, and some Chinese herbal
medicines. Methyl salicylate, for example, is found in a Chinese medicine called oil
of wintergreen, gaultheria oil, sweet birch oil, betula oil, and teaberry oil.
Aspirin poisoning can happen in children, but it's less common now because the medicine
is packaged in child-resistant containers. Also aspirin can cause Reye syndrome in
children and teens. Reye syndrome is a potentially life-threatening condition, so
aspirin should never be given to children.
Aspirin poisoning is still a concern, because some teens and adults take too much
aspirin on purpose.
Severe salicylate intoxication can be fatal. Taking too much aspirin, for example,
overwhelms your body's usual means of protection against poisoning. Your system may
start shutting down. You may go into a coma.
Why do I need this test?
You may have this test if it's possible you have overdosed on aspirin or other products
containing salicylates. Signs of an overdose include:
Abnormally deep or rapid breathing
Increased heart rate
Ringing in the ears (tinnitus)
Vertigo or dizziness
Too much acid in your bodily fluids
In addition, severe aspirin toxicity can change how your brain functions and how you
think. Symptoms include:
This test is required to confirm a diagnosis of aspirin intoxication. You may have
this test every 2 hours to watch your blood levels. It's likely you will have this
test until two tests in a row show that the concentration of aspirin in your blood
is lower than the peak measurement.
This test is also used to see how well treatment of the intoxication is working and
to find out whether more dramatic treatment measures are needed. For example, results
of this test can tell whether you need hemodialysis. This is a procedure that uses
a machine to clear your blood of toxins.
What other tests might I have along with this test?
You may have other tests to look at your salicylate toxicity level. These include:
Arterial blood gas, to look for acid-base balance
Electrolytes and glucose tests
Urinalysis, to watch the progress of the poisoning
Plasma creatinine, to find out whether you have kidney failure
Acetaminophen level, because some products contain both salicylate and acetaminophen
Your healthcare provider may also give you a physical exam and take your health history.
What do my test results mean?
Many things may affect your lab test results. These include the method each lab uses
to do the test. Even if your test results are different from the normal value, you
may not have a problem. To learn what the results mean for you, talk with your healthcare
If your healthcare provider prescribed aspirin for inflammation or arthritis, the
typical level of aspirin is between 10 to 30 milligrams per deciliter (mg/dL) of blood.
Any concentration above 40 mg/dL can be toxic.
In adults, taking 10 to 30 grams of aspirin can be fatal. Children may be fatally
poisoned by as little as 3 grams of aspirin. Because aspirin usually comes in tablets
that contain 81 mg or 325 mg, this would be as few as 9 tablets!
How is this test done?
The test requires a blood sample, which is drawn through a needle from a vein in your
Does this test pose any risks?
Taking a blood sample with a needle carries risks that include bleeding, infection,
bruising, or feeling dizzy. When the needle pricks your arm, you may feel a slight
stinging sensation or pain. Afterward, the site may be slightly sore.
What might affect my test results?
Too many blood fats (lipids) can interfere with test results. But lab workers may
remove any extra lipids from your sample through a process called lipemia.
How do I get ready for this test?
You don't need to prepare for this test. But be sure your healthcare provider knows
about all medicines, herbs, vitamins, and supplements you are taking. This includes
medicines that don't need a prescription and any illicit drugs you may use.