Serum or Plasma Ornithine Concentration (Quantitative)

Why This Test Is Done

Your healthcare provider may order this test if you have symptoms of liver disease, such as fatigue, jaundice (yellowing of skin/eyes), or confusion. It may also be used in research or specialized metabolic evaluations, such as those involving urea cycle disorders.

What to Expect Before the Test

No special preparation is needed unless instructed by your provider. You may be asked to fast for a few hours before the blood draw, but this isn’t always required. Bring any medications you’re currently taking to your appointment.

How the Test Is Performed

A healthcare professional will draw blood from a vein in your arm using a small needle. You may feel a slight pinch, but the procedure usually takes less than five minutes. The blood sample is then sent to a lab for analysis.

What the Results Mean

Results are typically reported as a concentration of ornithine in the blood, measured in milligrams per deciliter (mg/dL) or micromoles per liter (µmol/L). While reference ranges vary by lab, elevated levels may suggest liver dysfunction or metabolic issues, while very low levels could indicate certain genetic disorders.