Left adrenal hyperplasia may often be either hyperplasia of the left adrenal cortex, which is primarily due to enzyme defects, or hyperplasia of the medulla, which is of unknown etiology. Hyperplasia of the adrenal cortex is often congenital, a disorder caused by a defect in one of the enzymes involved in the synthesis of adrenocortical steroid hormones. Defects in the enzyme result in decreased corticosteroid synthesis and increased secretion of corticotropin-releasing hormone, which can stimulate adrenocortical hyperplasia. Adrenal medullary hyperplasia, the etiology of which is currently unknown, is a separate condition characterized by excessive secretion of autonomous catecholamines. It is categorized as purely primary and secondary. Patients with left adrenal hyperplasia are advised to consult a regular hospital in a timely manner and follow the doctor’s instructions for standardized diagnosis and treatment.