The short Synacthen test (SST) is a diagnostic procedure used to assess adrenal gland function, specifically to test for adrenal insufficiency. Here’s a brief overview:
- Baseline Cortisol Measurement: A blood sample is taken to measure the baseline level of cortisol.
- Administration of Synacthen: Synacthen, a synthetic form of adrenocorticotropic hormone (ACTH), is administered, usually as an intramuscular or intravenous injection.
- Post-Injection Cortisol Measurement: Further blood samples are taken at specific intervals, typically 30 and 60 minutes after the injection, to measure cortisol levels in response to Synacthen.
- Interpretation: The adrenal glands should respond to Synacthen by producing cortisol. A normal response is indicated by a significant rise in blood cortisol levels following the injection. If the cortisol levels do not rise appropriately, it suggests adrenal insufficiency.
The SST is particularly useful for diagnosing primary adrenal insufficiency (Addison’s disease) and secondary adrenal insufficiency due to pituitary or hypothalamic disorders.