Categories: Nephrology

Hypomagnesemia and Hypokalemia: Mechanism

Magnesium deficiency is often associated with refractory hypokalemia (In up to 50% of cases there is concomitant hypomagnesemia).

WHY? Exact mechanism isn’t known for certain.

PROPOSED MECHANISM: Low intracellular magnesium causes renal wasting of potassium. Normally magnesium will inhibit Renal Outer Medullary Potassium (ROMK) channels in the kidneys; however, hypomagnesemia allows the ROMK channel to efflux K+ into the urine.

NOTE: High Na+ uptake/ aldosterone states may also cause K+ loss (see image).

REFERENCES

  1. Chou-Long Huang and Elizabeth Kuo. Mechanism of Hypokalemia in Magnesium Deficiency. JASN October 2007 vol. 18 no. 10 2649-2652  
Get Medical Pearls directly to your inbox every week!
Weekly posts with high yield medical knowledge, directly to your mailbox!
Dr. C Humphreys

Internal Medicine

Recent Posts

Mechanism of a Mixed Apnea

Mixed apneas are characterized by absent respiratory effort and airflow in the first section of…

2 months ago

How Does Hypothyroidism Cause Hypoventilation?

Although rare, the differential diagnosis of hypoventilation and hypercapnia respiratory failure includes hypothyroidism. It is…

2 months ago

Why is Pro-BNP/ BNP lower in Obesity?

B-type natriuretic peptide (BNP) is a hormone created in response to cardiac wall stretch due…

8 months ago

What is Peribronchovascular Distribution on CT imaging?

A common finding described on computed tomography (CT) imaging. A disease with a peribronchovascular distribution…

1 year ago

Trapped Lung vs. Lung Entrapment

Though often used synonymously; Trapped Lung and Lung Entrapment technically describe separate entities along the…

2 years ago

Cause of Pericardial Effusion in Pulmonary Hypertension: Pathogenesis

It is not clearly understood why patients with pulmonary hypertension (PH) develop pericardial effusions. However,…

2 years ago

This website uses cookies.