Understanding Your Blood Test: Information for Patients
This test checks for acylcarnitine in your urine to help diagnose metabolic disorders that affect how your body converts food into energy.
{"Measures acylcarnitine levels in urine to detect metabolic disorders","Helps diagnose fatty acid oxidation disorders and organic acidemias","Often used for newborn screening and evaluating unexplained fatigue or muscle weakness","Abnormal results may indicate inherited metabolic conditions","Follow your doctor's instructions for proper urine collection"}
Key facts at a glance
- LOINC
- 43716-0
- Short code
- ACRNU
- Synonyms
- Acylcarnitine Ur Ql
- Category
- chemistry
- Sample
- urine
- Container
- Sterile urine collection container (plastic or glass)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 0 years
- Method
- Tandem Mass Spectrometry (MS/MS) or Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)
- CPT
- 82016
- SNOMED
- 413544009
- Specimen volume
- 5-10 mL preferred; minimum 2 mL
- Stability
- Room temperature: 24-48 hours; Refrigerated (2-8°C): 7 days; Frozen (-20°C or below): 30 days. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 24–72 hours
- Order
- routine
A blood test is a common laboratory procedure in which a small sample of your blood is collected and analyzed to help your doctor evaluate your overall health, screen for certain conditions, or monitor a medical problem you already have.
The acylcarnitine urine test detects the presence of acylcarnitine in your urine. Acylcarnitine is a substance produced when your body breaks down fatty acids for energy. This test helps doctors identify problems with fatty acid metabolism, which is crucial for converting food into usable energy.
The test is usually performed by a trained technician who cleans the skin on the inside of your elbow, wraps a band around your upper arm, and draws a small amount of blood into a tube with a thin needle. The sample is sent to a laboratory, and the procedure typically takes only a few minutes.
A urine sample is collected, typically in the morning after fasting, following specific preparation instructions from your healthcare provider. The sample is then sent to a laboratory where it is analyzed using specialized techniques to detect and measure acylcarnitine levels.
Your doctor may order this test as part of a routine checkup, to help find the cause of symptoms such as fatigue, fever, or unexplained weight change, to confirm or rule out a suspected condition, or to check how well a treatment or medication is working over time.
Your doctor may order this test if you have symptoms suggesting a metabolic disorder, such as unexplained fatigue, muscle weakness, low blood sugar, or unusual body odor. It is also commonly used in newborn screening programs to detect inherited metabolic conditions early.
In many cases little preparation is needed, but some blood tests require fasting for 8 to 12 hours beforehand. Drink plenty of water, tell your doctor about all medications and supplements you take, wear a sleeve that rolls up easily, and follow any specific instructions from your healthcare team.
Follow any fasting instructions provided by your doctor, typically fasting overnight before the test. Inform your doctor about all medications and supplements you are taking, as some may affect test results. Collect the urine sample as directed, usually in the morning.
Reference range
Not Detected / NegativeN/A
No special preparation required. Collect random urine specimen. Inform laboratory of any medications or supplements being taken, as certain compounds may interfere with testing.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Abnormal acylcarnitine levels in urine may indicate metabolic disorders such as medium-chain acyl-CoA dehydrogenase deficiency (MCAD), carnitine transport defects, or other fatty acid oxidation disorders. These conditions can lead to serious health problems if not diagnosed and treated early. The test helps healthcare providers differentiate between various metabolic conditions and guide appropriate treatment, which may include dietary modifications, medication, or specialized care.
Frequently asked questions
Does this test hurt?
How long does it take to get results?
What do abnormal results mean?
Is fasting required before the test?
Sources
- 1
- 2
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy