Specimen requirements
Sample type: Serum (Serum)
Collection requirements: No special requirements
Cost
Price on application
Turnaround time
Analytical method
Immunoassay - Indirect / Competitive
Analysis undertaken at these site(s)
- John Radcliffe Hospital
- Churchill Hospital
- Horton General Hospital
Reference intervals
09:00am cortisol <150 nmol/L - patient may have adrenal insufficiency (AI). Discuss with, or refer to Endocrinology.
09:00am cortisol 150 to 300 nmol/L - indeterminate, result may be normal. Interpret in the clinical context. Consider repeat test and Endocrinology consult.
09:00am cortisol > 300 nmol/L - adrenal insufficiency very unlikely.
NICE NG243
09:00am cortisol <50 nmol/L after overnight dexamethasone suppression excludes endogenous Cushing's syndrome.
A random (non-09:00am) cortisol or a value when the patient is taking steroid treatment is uninterpretable.
