Adrenal insufficiency tests help in determining whether the levels of cortisol are low or not. The following article provides information about the various tests done to check the levels of cortisol.
Adrenal insufficiency is an endocrine disorder where the adrenal glands stop producing substantial amount of steroid hormones, mainly cortisol. This condition may also affect the aldosterone production. Broadly, there are two types of adrenal insufficiency namely primary and secondary. The former can be further classified under three categories, one is idiopathic insufficiency, which is caused due to an unknown reason. The second subtype is caused due to Addison’s disease or autoimmune adrenalitis, which is an autoimmune disease. It can also be caused due to tumor of the adrenal gland. Secondary adrenal deficiency is a result of damaged hypothalamus or pituitary gland. The third subtype, which is not so significant, is the tertiary adrenal insufficiency. It is caused due to a hypothalamic disease.
Symptoms of Adrenal Insufficiency
It has been observed that the symptoms are similar to that of hypoglycemia, and the affected person experiences the following conditions.
- Chronic fatigue
- Loss of appetite
- Muscle weakness
- Weight loss
- Low blood sugar/Hypoglycemia
Besides the above mentioned symptoms, women tend to experience absent or irregular menstrual periods, and darkening of skin may occur in case of Addison’s disease.
The diagnosis is not as simple as it may seem. The symptoms progress at a very slow rate and the person tends to ignore them. Eventually when these symptoms become more serious then medical help is sought. If these symptoms are ignored, it could lead to adrenal crisis, where symptoms are more severe. The symptoms include sudden severe pain in the abdomen, lower back, and legs. Low blood pressure, dehydration, and losing consciousness are also some of the symptoms related to adrenal crisis.
Although analysis of this condition is difficult, there are certain tests that can be performed to determine adrenal inadequacy and its causes. Before advising various laboratory tests, the doctor reviews the history of the patient and the symptoms that are exhibited by the patient. Once the doctor establishes the relationship of the symptoms with deficiency of adrenal hormone, he recommends the various tests. These tests are mainly performed to check the cortisol levels, and to establish the cause of insufficient cortisol levels, if any.
ACTH Stimulation Test: The most common test is the ACTH (adrenocorticotropic hormone) stimulation test. In this test, an artificial form of ACTH is injected, and before and after this injection, the levels of blood and urine cortisol are measured. In people who are not affected by this condition there will be a rise in the levels of blood and urine cortisol; whereas, those with adrenal insufficiency will have a slight or no rise in the blood and urine cortisol levels.
CRH Stimulation Test: If the result of ACTH test is negative, a CRH (corticotropin-releasing hormone) stimulation test is conducted by the endocrinologist. In this test, artificial CRH is injected in the veins, and the blood cortisol level is measured at different intervals before and after the injection. While those with Addison’s disease, show increased production of ACTH, but no cortisol. People with secondary adrenal insufficiency show late or no production of ACTH. No ACTH response indicates that the pituitary gland is damaged, and a late ACTH response indicates the malfunction of the hypothalamus.
ACTH and CRH stimulation tests are the two major tests that help to identify the levels of cortisol. The treatment mainly involves replacing the hormones that are not being formed by the adrenal glands. An artificial glucocorticoid, such as prednisone, hydrocortisone, or dexamethasone is used as a substitute for cortisol. These hormones are available in the form of oral medications. If aldosterone is also found to be deficient then, it is substituted with fludrocortisone acetate or florinef.