Cortisol, Serum (Morning Sample)
Understanding Cortisol, Serum (Morning Sample)
What is Cortisol, Serum (Morning Sample)?
A cortisol test is done to measure the level of the hormone cortisol, a primary stress hormone which provides protective response to a perceived threat or danger. There are certain diseases, such as Addison’s disease and Cushing’s disease, which may affect the production of cortisol in the body.
This test is done to diagnose Cushing’s syndrome, Addison’s disease and to check the functioning of the adrenal gland.
The level of cortisol hormone rises and falls during the course of a day. These levels are highest in the early morning, drop slowly throughout the day reaching the lowest around midnight. Usually, the test involves drawing blood in the morning before 10 AM.
What is Cortisol, Serum (Morning Sample) used for?
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 pituitary glands
Interpreting Cortisol, Serum (Morning Sample) results
Interpretations
Normal cortisol levels in the blood:
· 6 to 8 a.m.: 10 to 20 µg/dL
· Around 4 p.m.: 3 to 10 µg/dL
· Around 12 a.m.: Less than 5 µg/dL
Normal cortisol levels may vary among individuals. Increased or decreased cortisol levels can be assessed only if the 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.
Reference range may vary from lab to lab*
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 the pituitary gland or pituitary tumors (secondary adrenal insufficiency)