Please explain "corticoid axis disturbance" I am being tested for cushing's disease.?

Cortisone. For practical purposes, the term describes a problem with the regulation of cortisone production. Cortisone is produced in the adrenal glands. This production is closely regulated by the thalamus and pituitary gland. A tumor in the pituitary region may disturb the production of cortisone or trigger increased production.