Signs and symptoms
The slowly progressive loss of cortisol and aldosterone secretion usually produces a chronic, steadily worsening fatigue, a loss of appetite, and some weight loss.
- Blood pressure is low and falls further when a person is standing, producing light-headedness.
- Nausea, sometimes with vomiting, and diarrhoea are common.
- The muscles are weak and often go into spasm.
- There are often emotional changes, particularly irritability and depression.
- Because of salt loss, a craving for salty foods is common.
Finally, the increase in ACTH due to the loss of cortisol will usually produce a darkening of the skin that may look like an inappropriate tan on a person who feels very sick.
Unfortunately, the slowly progressive chronic symptoms are usually missed or ignored until a sudden event like a flu virus, an accident, or the need for surgery suddenly precipitates a dramatic change for the worse because of the deficient response from the adrenals to one of these stresses. This is referred to as an adrenal crisis and is a medical emergency.
- A medical history of the symptoms mentioned above, especially hyperpigmentation (darkening) of the skin or gums, is often enough to raise a strong suspicion, prompting the appropriate tests.
- For autoimmune Addison's, the patient may already have been diagnosed with one or more of the typical associated conditions: premature ovarian/gonadal failure, a thyroid condition, vitiligo, B12 deficiency, insulin-dependent diabetes or coeliac (gluten/lactose intolerance).
- Even where the patient themselves has none of these associated conditions, a medical history of the extended family will often identify some of these associated conditions among first and second degree relations.
- Quite often, however, the first clue is from the abnormal results of routine blood tests ordered by the GP or hospital. These may include a low blood level of sodium, elevated blood level of potassium, a shift in the ratio of certain white blood cells, or surprising changes on an EKG or chest x-ray that are caused by high potassium or low blood volume. Other causes for these changes, particularly from medications, must be considered first.
- The ADSHG's explanatory leaflet for GPs, Diagnosing Addison's, explains the preliminary screening tests that your GP can conduct to indicate whether to refer you to a specialist for further testing.
- A definitive diagnosis of Addison's disease requires that definitive tests be carried out. The standard test used here is the short Synacthen test (also known as the ACTH stimulation test).
- The short Synacthen test is a blood test in which the amount of cortisol in the blood is measured before and after an injection of ACTH, usually over a period of 60 minutes. Individuals with adrenal disease produce a comparatively small amount of extra cortisol in response to the injection. Different hospitals apply different thresholds to define how small an increase in blood cortisol means adrenal failure. For Addison's, an elevated blood level of ACTH should also be found. For secondary adrenal insufficiency (a pituitary cause), ACTH is likely to be abnormally low.
- If the patient is very sick and Addison's disease is suspected, treatment can be initiated while the diagnostic tests are being done.
- Once the diagnosis of adrenal insufficiency is established, causation must be explored. Serology (antibody) tests are the first step. Where these are negative, further diagnostic screens are appropriate, including a CT scan of the adrenals and screening for tuberculosis or other infections through further blood and skin tests and x-rays.
Seeking medical help
- In the UK, you must ask your GP to refer you to an endocrinologist for specialist assessment in order for diagnosis of Addison's disease to be confirmed. It is important that all tests are carried out face-to-face under the supervision of qualified medical professionals.
Our thanks to Paul Margulies, M.D., F.A.C.P., F.A.C.E., Medical Director of the United States National Adrenal Diseases Foundation and Clinical Associate Professor of Medicine, Cornell University Medical College, whose text we have adapted in this section.
Further reading about diagnostic screening
- Diagnosing Addison's: a guide for GPs, Addison's Clinical Advisory Panel 2009 - 2016
- Consensus statement on the diagnosis, treatment and followup of patients with primary adrenal insufficiency, J Int Med. 2013
- Adrenal insufficiency, Society for Endocrinology 2016
- Clare's story, about how the advanced signs of Addison's were mistaken for anorexia. Clare Cooper died in February 2013, aged 23.