Primary adrenal insufficiency is caused by Addison's disease. what is secondary adrenal insufficiency caused by? (involved pituitary gland)

Occurs when the pituitary gland doesn't make enough of the hormone ACTH. Stoppage of Corticosteroid Medication Surgical Removal of Pituitary Tumours - ACTH-producing tumours of the pituitary gland that cause Cushing’s syndrome Tumours (most commonly adenoma), infection in the pituitary Loss of blood flow to the pituitary (eg. post partum haemorrhage