Adrenaline (Epinephrine) – Plasma Test Sample Type: Plasma Purpose: This test measures the concentration of adrenaline (epinephrine) in the plasma to assess adrenal medulla function, diagnose catecholamine-secreting tumors (e.g., pheochromocytoma), or investigate unexplained hypertension and stress-related disorders. About Adrenaline: Adrenaline is a catecholamine hormone and neurotransmitter produced mainly by the adrenal medulla. It plays a critical role in the body's "fight or flight" response, increasing heart rate, blood pressure, and blood glucose levels. Indications for Testing: Suspected pheochromocytoma or paraganglioma Episodes of sudden high blood pressure, palpitations, sweating, or headaches Autonomic dysfunction evaluation Monitoring stress responses in critically ill patients Preparation & Collection: The patient should rest quietly for at least 15–30 minutes before sample collection. Avoid caffeine, nicotine, and strenuous activity prior to the test. Blood is drawn into a tube containing EDTA, kept chilled, and plasma is separated and frozen promptly. Normal Reference Range (may vary by lab): < 100 pg/mL (can vary depending on posture and stress levels) Clinical Significance: Increased Levels: Pheochromocytoma, severe stress, hypoglycemia, acute heart failure, trauma Decreased Levels: Autonomic failure, certain adrenal insufficiencies