OHSU

Hormone Deficiencies

Your pituitary gland is a small organ about the size of a pea. It is attached to the underside of your brain. It makes many different hormones (chemicals that control your body functions). These hormones control other glands that produce their own hormones. Because it controls other glands and many body functions, doctors sometimes call it the "master gland."

A deficiency (lack) of pituitary hormones can be caused by: 

  • Surgery on the pituitary gland
  • Radiation treatment to your head
  • Disease that invades the pituitary gland area
  • Trauma (accident or injury)
  • Genetic (hereditary) condition

Pituitary hormone deficiency is usually caused by benign (non-cancerous) tumors called macroadenomas. These tumors can press on the pituitary gland and destroy cells that make hormones you need. This causes hormone deficiency (not enough pituitary hormones). Because the pituitary gland controls other glands, this damage can affect other body systems.