The goals with testing for pituitary disorders are to detect excess or deficient hormone production, determine the cause, and evaluate the severity of the condition. Testing frequently includes measurements of both the hormones that the pituitary produces, such as TSH, and the hormones of other endocrine glands that the pituitary is responsible for stimulating, such as the thyroid gland hormone thyroxine. Pituitary hormones are released as needed. Concentrations may be relatively constant in the blood, such as TSH, may vary over the course of a day, such as GH, over a cycle, such as FSH and LH, during the menstrual cycle, or be present in specific situations, such as prolactin in a lactating woman or ACTH as a response to a physical or emotional stress. This may lead to the need for suppression or stimulation challenge tests to detect hormone excesses and deficiencies. Medications are given to stimulate or suppress hormone production so that the change can be measured. It may also lead to the measurement of a related test, such as the measurement of IGF-1 (insulin-like growth factor-1), which reflects total GH production, along with the measurement of GH.

Testing may be used to help diagnose a pituitary disorder and may be ordered at intervals to monitor the effectiveness of treatment. Since treatments may not completely resolve the condition or may cause additional pituitary dysfunction in the present (such as surgery) or future (such as radiation) and because some inherited conditions may present a lifetime risk of developing a pituitary disorder, long-term monitoring may be necessary in some cases.

Laboratory Tests

• Prolactin
• LH and FSH
• TSH and Thyroxine
• hCG (human chorionic gonadotropin) – to detect pregnancy
• ACTH, Cortisol, and Glucose
• GH and IGF-1

Non-Laboratory Tests

• MRI (magnetic resonance imaging)
• CT (computed tomography)
• Water deprivation test (may be used to help diagnose Diabetes Insipidus)