Quantities: Finding laboratory values
There are a few options to search Observation resources for lab tests. You can search for all lab tests or specific lab tests for all patients or a specific patient.
Request: Search query for all lab tests for a patient
The following search query uses the laboratory category to find all lab tests for a given patient.
![Request: Search query for all lab tests for a patient Request: Search query for all lab tests for a patient](img/search_labvalues_all_request.png)
Request: Search for a specific lab test for all patients
To find a specific lab test, you can use the LOINC code for that test and the code search parameter. For example, the following search query finds all Potassium tests (LOINC code 6298-4) across all patients.
![Response: Search for a specific lab test for all patients Response: Search for a specific lab test for all patients](img/search_labvalues_specific_request.png)
Request: Search for a value and quantity
You can also add a value-quantity search parameter to find, for example, potassium tests with a specific value. The following example searches for any potassium tests with a value below 4.0 mmol/L.
![Request: Search for a value and quantity Request: Search for a value and quantity](img/search_labvalues_valueqty_request.png)
Parent topic: FHIR Search operations