The adrenal glands are small glands located on top of each kidney. They produce hormones that you can't live without, including sex hormones and cortisol. Cortisol helps you respond to stress and has many other important functions.
With adrenal gland disorders, your glands make too much or not enough hormones. In Cushing's syndrome, there's too much cortisol, while with Addison's disease, there is too little. Some people are born unable to make enough cortisol.
Causes of adrenal gland disorders include
Genetic mutations
Tumors including pheochromocytomas
Infections
A problem in another gland, such as the pituitary, which helps to regulate the adrenal gland
Certain medicines
Treatment depends on which problem you have. Surgery or medicines can treat many adrenal gland disorders.
NIH: National Institute of Child Health and Human Development