Differential diagnosis of hypokalemia, what are the signs

If you often experience vomiting, nausea, and stomach discomfort, you must go to the hospital for testing. You may be suffering from hypokalemia. Before people seek treatment for this disease, they must pay attention to the diagnosis. Therefore, you can understand the signs and make a differential diagnosis of hypokalemia.

1. Primary aldosteronism

The main clinical manifestations are hypertension and hypokalemia, and periodic paralysis and tetany may occur. Aldosterone in plasma and urine increased significantly, and the activities of plasma renin and angiotensin decreased. This disease is caused by tumors or hyperplasia of the zona glomerulosa of the adrenal cortex, which secretes large amounts of aldosterone. It can be diagnosed based on the above characteristics and laboratory tests. However, care should be taken to differentiate this condition from hypokalemia caused by the use of potassium-excreting diuretics or chronic diarrhea in patients with primary hypertension. It should also be differentiated from patients with rapid hypertension and renal artery stenosis due to secondary aldosterone increase and hypokalemia.

2. Hypercortisolism

It is caused by excessive secretion of cortisol due to adrenal cortical hyperplasia or tumor. Patients present with central obesity, hypertension, purple striae and acne, often accompanied by hypokalemia and metabolic alkali poisoning. Urinary 17-hydroxycorticosteroids are elevated, plasma cortisol is increased, and the circadian secretion rhythm disappears. The typical case is not difficult to diagnose.

(III) 17a-hydroxylase deficiency and 11p-hydroxylase deficiency

17a-hydroxylase deficiency can lead to insufficient synthesis of glucocorticoids (cortisol) and sex hormones, while 11p-hydroxylase deficiency only impairs the synthesis of cortisol. Both of the above can lead to compensatory increase in ACTH secretion, resulting in excessive synthesis and secretion of deoxycorticosterone (mineralocorticoid), leading to hypertension and hypokalemia. Patients with 17a-hydroxylase deficiency also have insufficient synthesis of sex hormones, so the development of secondary sexual characteristics of both boys and girls is impaired, while 11p-hydroxylase deficiency is also accompanied by excessive secretion of androgens, so female patients become masculinized and male patients experience precocious puberty, which can be used for differentiation.

(IV) Renal tubular acidosis

Except for type IV, the other three types of renal tubular acidosis (type I, type II, and type III) all have obvious hypokalemia, hyperchloremia, and metabolic acidosis, while the urine is alkaline (urine pH is above 6). It is often accompanied by a decrease in blood sodium, calcium, phosphorus, etc., and routine urine examination often shows no abnormalities.