Good to knowOne result rarely tells the whole story. Your provider looks at your results together with your symptoms, exam, and other tests.
What the test is
The sample must be handled quickly, on ice, for accurate results.
Why it's done
- Confusion or sleepiness in someone with liver disease
- Some metabolic disorders in babies
- Valproate side effects
Getting ready and what happens
- Avoid smoking and exercise beforehand.
How the test is done
- A health worker cleans the skin, puts a band around your arm, and draws blood from a vein with a small needle. It takes a few minutes.
What the results mean
High
Can point to liver failure, a metabolic disorder, or a medicine effect. In cirrhosis, treatment of confusion is based on symptoms more than the number.
When a result needs quick action
Call 911New confusion, extreme sleepiness, or unresponsiveness
Questions to ask your provider
- What do my results mean for me?
- Do I need to repeat this test or have other tests?
Risks
A blood draw is very safe. You may have slight pain or a small bruise where the needle went in.
Related conditions
Related medicines
Related tests
Sources
Last updated 2026-11-13.