Differential Diagnosis Test
A differential diagnosis is a step-by-step process your provider uses to figure out which condition is causing your symptoms when many conditions could be the cause.
What this test measures
It is not a single test but a process that creates a list of possible conditions based on your symptoms, medical history, family health history, medicines, lifestyle, and test results. This list helps your provider decide which tests to order to confirm or rule out conditions.
What your results mean
Reference ranges vary by laboratory and by your age and sex. MedlinePlus does not publish a single normal range for this test — always read your result against the range printed on your own lab report and discuss it with your provider.
Frequently asked questions
What is a differential diagnosis?
It is a list of possible conditions that could be causing your symptoms, created by your provider based on your symptoms, medical history, and other factors.
How is a differential diagnosis made?
Your provider follows a step-by-step process, starting with a list of all possible conditions that match your symptoms, then uses tests to narrow down the list.
What goes into the differential diagnosis list?
The list is based on your symptoms, medical history, family health history, medicines and supplements, lifestyle, and test results.
How do test results affect the differential diagnosis?
Test results can narrow the list, rule out certain conditions, suggest additional tests, point toward a likely diagnosis, or guide early treatment choices.
Is the differential diagnosis the same as the final diagnosis?
No. The differential diagnosis list is not your final diagnosis. It is only the possible conditions that could be causing your symptoms.
Related lab tests
Sources
- MedlinePlus: Differential Diagnosis — NIH MedlinePlus
Last updated . Information is aggregated from official public sources and is not a substitute for professional medical care.