Medical tests comprising blood and urine tests are used in diagnosing Cushing's syndrome (a glandular disorder caused by excessive cortisol) and Addison's syndrome, (a glandular malfunction caused by the failure of the cortex and distinguished by a deficiency of red blood cells), which are two life-threatening adrenal-related diseases. Some doctors also use salivary cortisol to analyze Cushing's syndrome as well as to assess possible stress-associated diseases, although these uses are not widely circulated. Urine and saliva tests are commonly used to assess the excess production of cortisol.
Once an abnormal cortisol concentration has been detected, the doctor will recommend additional testing to help confirm the excess or deficiency of the hormones and to help determine its cause. Among normal individuals, the levels of cortisol tend to drop during bedtime and are most prominent just after awakening. These levels can alter if a person works unpredictable shifts (such as the work shift during the night - as midnight to 8 a.m.) and rests at varied times during the day.
The patterns of cortisol levels are typically lost in a patient suffering from Cushing's syndrome. A heightened cortisol concentration during the day that does not drop during any part of the day is an indication of cortisol overproduction. If the superfluous cortisol is inhibited during dexamethasone suppression test, it indicates that the overproduction of cortisol is a result of an enhanced pituitary adrenocorticotrophic hormone (ACTH) output. If the cortisol levels are not suppressed even with the dexamethasone suppression test, it indicates that the individual is suffering from an ACTH. This could result from a developing tumor outside of the pituitary gland or due to a specific drug regimen taken by the patient for another unrelated condition.
If the cortisol test resultsshow that the adrenal glands are hyperactive, then the patient might be suffering from Cushing's disease. The symptoms of the disease take place due to extended exposure of the body to too much cortisol in the body. The excess production of cortisol in this case could be due to the overproduction by the adrenal glands, which is an indication of a harmless adrenal tumor, or excessive ACTH stimulation due to the pituitary or other ACTH developing tumor.
Once an irregularity has been discovered and affiliated with the endocrine gland, adrenal cortex, or other cause, then the doctor may use additional and extensive screening such as CT (computerized axial tomography) or MRI (magnetic resonance imaging) scans to ascertain the origin of the surplus (such as a pituitary gland, adrenal gland, or other abnormal new mass) and to measure the levels of any impairment to the glands.