What is adrenal insufficiency?
Adrenal insufficiency is a condition in which the adrenal glands do not make enough hormones. The adrenal glands make cortisol, aldosterone and androgen (testosterone-like) hormones.
- Cortisol is a steroid hormone that is important for managing blood pressure, blood sugar and energy. In times of illness, it is a life-saving hormone.
- Aldosterone is a hormone that helps manage the body’s blood pressure by keeping the body’s salt and water in a normal range. Without aldosterone, the kidney loses too much salt and water and holds onto too much potassium. This causes low blood pressure and high potassium levels in the blood.
- Androgens are male sex hormones that are important for growth and puberty.
What causes adrenal insufficiency?
Adrenal insufficiency can be “primary,” which involves lower amounts of the cortisol and aldosterone hormones. It can also be “secondary,” which involves lower amounts of the cortisol hormone.
- Primary adrenal insufficiency is caused by damage to the adrenal gland, which is sometimes from an autoimmune disorder called Addison’s disease. An autoimmune disorder is when the body’s infection-fighting proteins accidentally fight and kill its own cells – in this case, adrenal cells. Other causes are infection, cancer and bleeding in the adrenal glands. Congenital adrenal hyperplasia is another form of adrenal insufficiency. Primary adrenal insufficiency most often decreases the amount of cortisol and aldosterone.
- Secondary adrenal insufficiency is caused by a problem with the pituitary gland. The pituitary is a small gland in the brain. It makes a hormone called adrenocorticotropic hormone (ACTH), which tells the adrenal gland to make the cortisol hormone. If the pituitary is not working, the adrenal glands will not make cortisol. This can be caused by abnormal pituitary growth, brain injury, infection or cancer.
A special form of secondary adrenal insufficiency can happen when a person takes steroid medicines for a long time as a treatment for another disorder like asthma or arthritis. Because the pituitary senses that there is already a lot of cortisol hormone in the body, it does not tell the adrenal glands to make cortisol. After a time, the adrenal gland will become smaller and less able to make cortisol. If steroid treatments are suddenly stopped, the adrenal glands don't have enough time to rebound and make cortisol. Without cortisol, the body can become sick. This type of secondary adrenal insufficiency can be treated by slowly reducing steroid medicine and providing higher doses during times of illness to mimic what the body would typically do on its own when it is stressed.
What are the signs and symptoms of adrenal insufficiency?
- Feeling very tired or irritable
- Darkening of the skin
- Symptoms of low blood pressure such as lightheadedness, confusion and difficulty concentrating
- Salt cravings
- Symptoms of low blood sugar such as shakiness, sweating and fatigue
- Nausea, vomiting (throwing up), diarrhea (loose bowel movements) or stomach pain
- Mood changes
- Sodium (salt) and potassium problems
What tests are used to diagnose adrenal insufficiency?
Your child’s healthcare provider may order blood tests to measure the following:
- Hormone levels (ACTH, cortisol and aldosterone)
- Sodium, potassium and blood sugar levels
- Special studies to identify causes of adrenal insufficiency, such as Addison’s disease
A test called an ACTH stimulation test may be done to see how well the adrenal glands are working. For this test, the pituitary hormone ACTH is given through an IV or as an injection into the arm. If the adrenal glands are working, they will make a lot of cortisol (which is checked at 30 and 60 minutes after the injection) in response to this injection. Blood will be taken to measure how well the adrenal glands react to the ACTH. Pictures (like an MRI) of the pituitary or adrenal glands may also be needed to make the diagnosis.
How is adrenal insufficiency treated?
The treatment for adrenal insufficiency depends on which hormones the body is not making. Some medicines used to treat adrenal insufficiency include:
- Steroids: These steroids replace the cortisol that your body is not making. The most common drug treatment is hydrocortisone, which is taken 2 to 3 times a day by mouth. Other drug choices are prednisone or dexamethasone.
- Steroid shots: An injection (shot) of steroid may be needed when there is vomiting, or if medicines cannot be taken by mouth.
- Fludrocortisone: This steroid helps manage the salt balance in the body.
- Salt replacement: Salt tablets may be needed to keep the salt balance normal.