Reference ranges
Direct bilirubin reference range
Reference ranges describe the interval a laboratory prints next to your result. They are not a diagnosis of what is “normal” for you personally — your clinician interprets results in context.
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What Direct bilirubin measures
Labs may report direct (conjugated) bilirubin separately from total bilirubin to show how the liver is handling this pigment.
Why ranges differ
Laboratories set their own reference intervals using their methods, equipment, and population data. That is why the range on your Quest report may differ from a LabCorp report — always use the interval printed on your source document.
Common units
Direct bilirubin is often reported in mg/dL. Confirm units on your original report before comparing values across time.