Overview of Cortisol
What is Cortisol?
Why is Cortisol done?
The Blood Cortisol Test is performed:
· To diagnose Cushing’s syndrome caused due to high cortisol levels
· To diagnose Addison’s disease
To detect and diagnose conditions of the adrenal glands or the pituitary glands
What does Cortisol Measure?
Cortisol is a hormone secreted by the adrenal glands that helps in the metabolism of carbohydrates, fats, and proteins. It also plays a regulatory role in maintaining the blood sugar levels, water balance of the body, and is also essential in the maintenance of a healthy immune system. Most cortisol in the body is found bound to proteins, and only a small portion remains free and metabolically active.
Level of cortisol hormone rises and falls during the course of a day following a diurnal pattern. Cortisol levels are highest in the early morning, drops slowly throughout the day reaching its lowest around midnight, and again increases slowly through the night to reach its highest early next morning. This diurnal pattern of cortisol secretion is maintained by the hypothalamus in the brain and pituitary gland located just below the below the brain. Fall in the blood cortisol levels stimulates the production of Corticotropin Releasing Hormone (CRH) from the hypothalamus. CRH stimulates the pituitary gland to secrete the Adrenocorticotropic Hormone (ACTH), which in turn stimulates the production of cortisol from the adrenal glands to increase cortisol levels in blood. Cortisol levels are regulated by a feedback mechanism. When cortisol levels rise to the required levels, CRH secretion from hypothalamus is stopped, which in turn stops ACTH secretion from pituitary, thereby stopping cortisol secretion from the adrenal glands. Symptoms associated with increased or decreased levels of cortisol hormone appear when this feedback mechanism is disturbed due to diseases or lifestyle.
Preparation for Cortisol
- No special preparation required
Sample Type for Cortisol
Interpreting Cortisol results
Normal cortisol levels may vary among individuals. Increased or decreased cortisol levels can be assessed only if cortisol level in blood does not follow the diurnal pattern as it should.
Cortisol levels may fall outside the normal range for the time of day due to diseases or due to lifestyle factors such as irregular sleeping times.
Causes of increased cortisol levels:
· Long term treatment with glucocorticosteroid hormones like prednisone, dexamethasone, etc.
· Pituitary tumors that increase ACTH production
· ACTH producing tumors in other parts of the body
· Adrenal tumors that increase cortisol secretion
· Congenital Adrenal Hyperplasia, a disease which causes excessive growth of adrenal gland cells
· Recent surgery, illness, injury, or sepsis
· CRH producing tumors in rare cases
Causes of decreased cortisol levels:
· Reduced cortisol production due to damage or diseases of the adrenal gland (primary adrenal insufficiency) like Addison’s disease
· Reduced ACTH production due to reduced activity of pituitary gland or pituitary tumors (secondary adrenal insufficiency)
Answers to Patient Concerns & Frequently Asked Questions (FAQs) about Cortisol
Frequently Asked Questions about Cortisol