Serum/plasma cortisol and glucose with 24-hour urine free cortisol and plasma arginine vasopressin (AVP) profile

What Does Each Part Measure?

Your blood sample will be tested for cortisol, a hormone produced by your adrenal glands that helps regulate stress responses, metabolism, and immune function. Glucose levels are also measured to check blood sugar balance. Urine is collected over 24 hours to measure free cortisol, which helps identify cortisol secretion patterns. Plasma arginine vasopressin (AVP), also called antidiuretic hormone (ADH), is measured to assess fluid retention and hydration status.

Why Might This Test Be Ordered?

Your doctor may recommend this test if you have symptoms like unexplained weight changes, fatigue, high or low blood pressure, frequent urination, or signs of hormonal imbalances. It can also be used to evaluate conditions such as Cushing’s syndrome, adrenal insufficiency, diabetes, or disorders affecting fluid and electrolyte balance.

Sample Collection and Preparation

Blood samples are drawn from a vein, usually in your arm, while urine is collected in a container over a full 24-hour period. Follow your healthcare provider’s instructions carefully to ensure accurate results. Avoid alcohol or certain medications before testing if directed.

Preparation and Restrictions

Typically, no special preparation is needed for blood tests, but you may be advised to avoid caffeine or certain medications that could affect cortisol levels. For urine collection, drink usual fluids and follow your provider’s guidelines to avoid contamination. Avoid smoking or strenuous activity before testing if recommended.