Cortisol blood test
• NOTE:: Please include all relevant clinical history in sample order
Normal Reference Range
140 – 700 nmol/L
Test Information
The pituitary gland’s adrenocorticotropic hormone (ACTH) stimulates the production and secretion of cortisol. Cortisol levels that are excessive are indicative of Cushing’s syndromes, in which the excess is brought on by ectopic ACTH secretion (such as in small cell lung cancer), exogenous corticosteroid use, pituitary adenoma, or adrenal hyperplasia or neoplasia. Contrarily, common reasons of reduced cortisol synthesis include Addisonian spectrum disorders, CAH, autoimmune and iatrogenic-mediated adrenal damage, amyloidosis, and certain infections.
Clinical Indications
• Insufficient cortisol levels/Addison’s disease: weight loss, weariness, muscle weakness, low blood pressure, or abdominal pain. An adrenal crisis (also known as an Addisonian crisis) brought on by stress may necessitate emergency medical intervention.
• Cushing’s symptoms include high blood pressure, high blood sugar, obesity, brittle skin, hyperpigmentation, weak muscles, and osteoporosis. presentation of irregular menstruation in women or low stature/delayed development in youngsters.
Sample Required
5mL serum sample tube is required for a Cortisol blood test
Min. sample volume
1.0mL
Special Instructions and Precautions
• NOTE:: Please include all relevant clinical history in sample order
Time Limits For Retrospective Testing
5 days
Patient Preparation
Therapeutic glucocorticoids (prednisolone, methyl-prednisolone, and hydrocortisone) may interfere with the cortisol assay. In cases where this is not possible, therapy with such steroids should be stopped and replaced with an alternate steroid (e.g., dexamethasone, betamethasone) at an equivalent dose (see BNF section 6.3.2) at least three days prior to the test.
Any factors affecting the test
Not applicable
Turnaround Time
4 hrs
Referral centre (if applicable)
Details of referral laboratory available on request
Test Code
CORT