The normal value of blood aldosterone level is 342.6~1436.6 pmol/L, exceeding the upper limit of normal is aldosteronism. It may be caused by diseases such as adrenocortical tumors, and may trigger serious consequences without timely intervention. The upper limit of normal for aldosterone fluctuates widely in normal people. For those on a low-sodium diet, the upper limit of normal is 980.0 pmol/L in the prone position and 1436.6 pmol/L in the upright position. For those on a regular diet, the upper limit of normal is 342.6 pmol/L in the prone position and 663.9 pmol/L in the upright position. Blood aldosterone exceeding the upper limit of normal suggests the presence of aldosteronism, which can be caused by adrenocortical tumors or hyperplasia, hypertension, heart failure, nephrotic syndrome, and other disorders. These disorders can be life-threatening if not intervened in a timely manner, and are serious enough to require timely treatment. However, blood aldosterone exceeding the upper limit of normal may also be due to a prolonged low-sodium diet, a situation that can be corrected by diet and is not serious. Abnormally elevated blood aldosterone levels are recommended for prompt hospitalization.