Lateral nodular thickening of the left adrenal gland is generally defined as an increase in localized volume of the lateral left adrenal gland on imaging. Lateral nodular thickening of the left adrenal gland may be more serious as it may be due to diseases such as adrenocortisolism, primary aldosteronism, and congenital adrenocortical hyperplasia. 1. Adrenocorticotropic hyperplasia: It is caused by excessive secretion of glucocorticoids (mainly cortisol) from the adrenal cortex due to a variety of reasons. Imaging may show nodular thickening of the left lateral adrenal gland. 2. Primary aldosteronism: It is mainly caused by excessive secretion of aldosterone by adrenal cortex, and imaging may show nodular thickening of the left lateral adrenal gland. 3. Congenital adrenocortical hyperplasia: congenital gene mutation can lead to certain adrenocorticotropic hormone synthetizing enzyme defects in the body, thus triggering adrenocortical hyperplasia, and the imaging examination can suggest that the left lateral adrenal gland nodular thickening. Once the left lateral adrenal nodular hyperplasia occurs, it is necessary to consult a doctor in time.