Exams and Tests

Blood tests may be performed to determine which hormone is low or absent.

• Tests for insulin-like growth factor-I (IGF-I) or insulin-like growth factor binding protein-3 (IGFBP-3) may be performed to detect growth hormone deficiency. Additional testing may also be required.
  
  
• Morning serum cortisol levels and a 24-hour urinary free cortisol may be measured to screen for CRH (corticotropin-releasing hormone) deficiency or ACTH deficiency. CRH or ACTH stimulation tests may also be performed.
  
  
• For hypothyroidism (a condition involving decreased production of thyroid hormone), the doctor performs simple blood tests for free thyroxine (a hormone contained and released from the thyroid gland) and TSH.
  
  
• Tests to determine LH or FSH deficiency vary based on the patient's age.

• Tests for prolactin levels in the blood may be performed.

• If urine specific gravity (a test of how dilute or concentrated the urine is) is low and urine volume is high with excessive thirst, testing for diabetes insipidus may be performed. Note diabetes insipidus ("water diabetes") is completely unrelated to diabetes mellitus ("sugar diabetes"), the more common kind of diabetes.

The doctor may obtain an MRI of the brain to assess the structure of the pituitary or to detect a tumor.