What causes Adrenal Insufficiency

What causes Adrenal Insufficiency?

Autoimmune Disorders

In up to 80 percent of Addison’s disease cases, the adrenal cortex, the outer layer of the adrenal glands, undergoes gradual destruction by the body’s immune system. This process is characteristic of autoimmune disorders, wherein the immune system produces antibodies that target and gradually dismantle the body’s own tissues or organs.

Adrenal insufficiency arises when approximately 90 percent of the adrenal cortex is destroyed, leading to a deficiency in both cortisol and aldosterone. This condition can affect solely the adrenal glands or may involve other endocrine glands, as seen in polyendocrine deficiency syndrome.

Polyendocrine deficiency syndrome manifests in two forms: type 1, typically inherited and appearing in children, and type 2, often termed Schmidt’s syndrome, which commonly affects young adults.

Type 1 polyendocrine deficiency syndrome may include:

  • Hypoparathyroidism, leading to imbalances in calcium and phosphorus levels.
  • Delayed sexual development.
  • Pernicious anemia.
  • Chronic candida infections.
  • Chronic active hepatitis.

Conversely, type 2 polyendocrine deficiency syndrome, believed to have a hereditary component due to its familial occurrence, presents with:

  • Hypothyroidism.
  • Delayed sexual development.
  • Diabetes.
  • Vitiligo.

Tuberculosis (TB) historically played a significant role in adrenal insufficiency cases, particularly in the 19th century when it was the primary cause identified by Dr. Thomas Addison. However, with improved TB treatments, its contribution has declined to less than 20 percent in developed nations.

Other less common causes of Addison’s disease encompass:

  • Chronic infections, predominantly fungal.
  • Metastatic cancer affecting the adrenal glands.
  • Amyloidosis, resulting in abnormal protein accumulation and organ damage.
  • Surgical removal of the adrenal glands.
  • Adrenal involvement in AIDS-associated infections.
  • Adrenal hemorrhage.
  • Genetic anomalies affecting adrenal gland development, responsiveness to ACTH, or hormone production.

Causes of Secondary Adrenal Insufficiency

Secondary adrenal insufficiency arises from a deficiency of adrenocorticotropic hormone (ACTH). In the absence of ACTH stimulation, cortisol production by the adrenal glands decreases, while aldosterone production typically remains unaffected.

Temporary secondary adrenal insufficiency can occur when individuals who have been on long-term treatment with synthetic glucocorticoid hormones like prednisone abruptly discontinue their medication. This abrupt cessation can disrupt the body’s natural cortisol production.