Description
Why It’s Done:
This test is ordered to:
• Diagnose or evaluate causes of abnormal water balance, such as diabetes insipidus (characterized by excessive urination and thirst)
• Investigate hyponatremia (low sodium levels) or fluid retention conditions like syndrome of inappropriate ADH secretion (SIADH)
• Assess pituitary gland function or disorders affecting ADH secretion
• Monitor treatment effectiveness for conditions related to ADH imbalance
Preparation:
• Follow any specific instructions from your healthcare provider regarding fluid intake; sometimes fasting or water restriction may be required before the test
• Blood is drawn from a vein, usually in the arm
• Inform your healthcare provider about any medications, especially those affecting fluid balance or hormone levels
• Fasting requirements depend on the clinical scenario, so confirm with your doctor
