Who is more likely to get addison's disease?

Other gland failures. Most addison's is autoimmune, and occurs in people with other autoimmune diseases, such as hashimotos thyroiditis, type 1 diabetes, hypogonadism, hypoparathyroidism, and others. But it can happen by itself. Besides autoimmune, it can result from adrenal hemorrhage, tb, hiv, tumors, and other causes.
Other endocrine dz. People who have other autoimmune endocrine disease like thyroid disease or pituitary disease.