How Is Addison's Disease Diagnosed?
Addison's disease results from bilateral destruction of the adrenal glands, which sit atop your kidneys. Your adrenal glands are stimulated by your brain to produce cortisol under stress. Addison's disease can present as an acute illness or come on gradually. A rare complication of Addison's disease is adrenal crisis (also called primary adrenal insufficiency), which presents as shock, or very low blood pressure. The risk of an adrenal crisis increases if you have an infection or surgery, or experience any major physical stress.
With chronic Addison's, the symptoms are vague and non-specific. Addison's disease can be difficult to diagnose, and it often takes years for a diagnosis to be made. Symptoms of Addison's disease include
- Fatigue and weakness
- Poor appetite and weight loss
- Nausea, vomiting, and abdominal pain
- Muscle and joint pain
- Low blood pressure
Some abnormalities that may be seen on routine blood work that point to Addison's disease include a low sodium or high potassium level, anemia (low iron) or a high level of eosinophils (a kind of white blood cell). Often times, it's first detected through routine blood tests in a hospital or doctor's office to check for sodium and potassium levels. The doctor will also check for hyperpigmentation, or darkening, of the skin or gums -- a sign of long-term Addison's disease.
The most definitive way to diagnose the condition is to measure hormone levels in the blood before and after giving ACTH. ACTH is a hormone in the brain that, when released, normally increases cortisol release from the adrenal glands. With Addison's disease, which is equivalent to primary adrenal insufficiency, the adrenal glands cannot respond to ACTH stimulation, and cortisol levels remain low. Measuring cortisol and ACTH levels can help determine if adrenal insufficiency is present, and if so, whether the problem is with the adrenal glands or brain.
An evaluation of Addison's disease can include a CT scan of the adrenal glands to look for infection, cancer, or bleeding in the adrenal glands. A tuberculosis test may be done, as well, because up to 20% of cases are caused by tuberculosis. The majority, however, are auto-immune.
What Are the Treatments for Addison's Disease?
Because Addison's disease is caused by a lack of normal hormones produced by the adrenal glands, it can be treated by replacing those hormones. This can be done with once- or twice-daily tablets of hydrocortisone, a steroid hormone. If needed, aldosterone can be replaced with a synthetic steroid, fludrocortisone acetate (brand name Florinef), which is taken orally once a day. These medications need to be increased during times of stress, infection, surgery, or injury.
Treatment is almost always completely successful. When treated, people with Addison's disease can lead a full and normal life. It is, however, important to carry a medic alert bracelet and emergency ID card at all times and to keep a small supply of medications at work or school. Even missing one dose can be dangerous.
In patients suspected of having an Addisonian crisis, doctor-prescribed injections of salt, fluids, and glucocorticoid hormones may be given immediately -- even before a diagnosis of Addison's disease is confirmed.