Adrenal insufficiency, also known as Addison's disease, is an autoimmune condition. Though the features overlap, it is different than adrenal fatigue. Autoimmune diseases like Addison's disease and systemic lupus erythematosus (SLE) occur when the body develops antibodies against itself.
The most common cause of Addison's disease is the production of antibodies that are directed against the adrenal glands. Because of these antibodies, the adrenal glands are unable to produce hormones such as cortisol and aldosterone. Some of the symptoms of this condition overlap with the adrenal decline stage of adrenal fatigue. Here are some key symptoms that can suggest Addison's disease:
When this condition first begins, you may experience fatigue, lightheadedness, and orthostatic hypotension (a drop in blood pressure when moving from lying down to either a sitting or standing position).
Another classic finding is hyperpigmentation. You may see these pigmented areas along the creases of your hands.
You may notice decreased hair growth under your armpits or in your pubic area.
Key lab findings on blood work can include low sodium levels (hyponatremia) and high potassium levels (hyperkalemia).
The diagnosis of Addison's disease can be confirmed by blood tests:
Your healthcare provider may suspect a diagnosis of Addison's disease if you have a low cortisol level, usually less than 5 milligrams per deciliter in a blood test conducted in the morning.
If cortisol is low, then you need a confirming test, namely an adrenal gland challenge called a cosyntropin stimulation test. With this test, your healthcare provider measures your baseline cortisol, intravenously injects cosyntropin (a synthetic derivative of ACTH, which is made in the pituitary gland), and measures your cortisol levels 30 and 60 minutes after.
A rise of 10 units above the baseline is usually considered an adequate response to ACTH. If this response is present, then Addison's disease is not.
Autoimmune conditions often occur together. If Addison's disease is diagnosed, it's highly probable another autoimmune condition is present. If you're diagnosed with Addison's disease, look for other autoimmune conditions. Examples include Type I diabetes mellitus and hypothyroidism due to Hashimoto's thyroiditis.
The treatment of Addison's disease consists of medications to substitute for both cortisol and aldosterone. They include hydrocortisone, which is a synthetic cortisol that's given to help restore blood pressure, given that the adrenal gland is unable to make cortisol.
A dreaded complication of Addison's disease is an Addisonian crisis. This occurs in the setting of an acute stressor, such as an infection. The adrenal glands can't make enough cortisol to deal with the stressor. The affected person often presents with very low blood pressure in a condition called shock.
The treatment involves intravenous steroids, such as hydrocortisone, which can be life-saving. If you've been diagnosed with Addison's disease and you're already on steroid replacement, then this medication needs to be increased during the time of an acute stressor, such as a really bad infection.