“High adrenaline” generally refers to elevated plasma free adrenaline, which can be used to assist in the diagnosis of pheochromocytoma. If a plasma free adrenaline level is elevated again in a patient who has had a pheochromocytoma, it may indicate a recurrence of the tumor. Preparation for the plasma free epinephrine test is important to obtain accurate results. It is important to stop taking epinephrine or adrenal-type medications 1 week before the test, stop taking acetaminophen for 48 hours, and fast for 8 to 10 hours before the blood is drawn. Consumption of caffeine-containing foods, coffee, tobacco, tea, or ethanol-containing beverages can affect test results. Pheochromocytoma has a variety of clinical manifestations, caused by increased catecholamines in the blood, with hypertension as the main symptom as well as metabolic disturbances. When high plasma free adrenaline is detected, it is recommended to go to the hospital and seek medical advice from your doctor.