What is this test?
Insulin is the hormone that helps glucose enter cells. A measured level is meaningful only in relation to glucose, fasting status, collection time and any glucose-lowering medicine.
Why might it be ordered?
- To investigate selected cases of low glucose or unusual insulin production.
- As part of a clinician-directed assessment of insulin resistance or beta-cell function.
What sample is needed?
A blood sample is required. The laboratory chooses the correct tube and handles the sample for this test.
How should you prepare?
Confirm whether fasting is required and how diabetes medicines should be handled. Do not change insulin or tablets without explicit instructions.
How should you understand the result?
There is no single insulin cutoff that diagnoses insulin resistance for everyone. The value must be paired with glucose and the clinical question.
Sources and editorial status
This patient-facing text is an editorial draft. It should be approved by a laboratory physician before official publication.