Adrenal tumors are localized mainly by imaging tests, including abdominal ultrasound, CT, and adrenal nuclear imaging. Characterization can be done by some special labs or tests. 1. Abdominal ultrasound: abdominal ultrasound is commonly used for the initial screening of adrenal tumors, but tumors with a diameter of <1 cm are easily missed. 2. CT: it is one of the most important examinations for diagnosing adrenal tumors, and the detection rate of adrenal tumors of various natures is more than 90%. Especially, enhanced CT is of great significance in identifying tumors of different natures. 3. Adrenal nuclear imaging: adrenal nuclear imaging is mainly used to identify adrenal adenoma, adrenal carcinoma, adrenal cortical hyperplasia and so on. 4. Special labs or tests: patients suspected of aldosterone tumors can undergo anamnesis test or postural test; patients suspected of tumors secreting a large amount of cortisol can undergo plasma free cortisol, urinary free cortisol and urinary cortisol metabolites, and high-dose dexamethasone test; those suspected of pheochromocytomas can undergo 24-hour urinary catecholamines and their metabolites, urinary vanillylmandelic acid, and blood catecholamine test. If adrenal tumor is suspected, it is recommended to go to the hospital as soon as possible, and ask the professional doctor to evaluate the condition and choose the appropriate examination and laboratory test, so as to make a clear diagnosis as soon as possible and then give the corresponding treatment.