Categories: Nephrology

Beer Potomania: Mechanism

WHAT IS IT? Hyponatraemia (dilutional) secondary to excessive alcohol consumption and undernourishment (i.e low protein/salt)

HOW? Malnourished chronic alcoholics with minimal solute/ protein intake are susceptible to water toxicity at small volumes (due to loss of urea concentrating gradient) compared to healthy individuals with normal renal function (normal adults can drink up to 20L a day without subsequent hyponatremia).

*Fluid intake over 4-5 L can push them into hyponatremia [Obligatory solute loss is ~250mOsm/day]


  • Free water excretion from the kidney depends on both urinary dilution capacity AND solute excretion
  • MAX urine diluting capacity= 50 mOsm/L
  • Beer potomania= LOW osmoles due to poor diet 
  • Hence the low solutes makes the kidneys HOLD onto the fluid because there are insufficient osmoles to allow for excretion of the water
  • So when you give solute, they undergo diuresis rapidly and are at risk of over correcting! ADH is SUPPRESSED due to all the volume retention!


  1. Bhattarai N, Kafle P, Panda M. Beer potomania: a case report. BMJ Case Reports. 2010;2010:bcr10.2009.2414. doi:10.1136/bcr.10.2009.2414.
  2. Sanghvi, S. R.,Kellerman, P. S. & Nanovic, L. Beer potomania: an unusual cause of hyponatremia at high risk of complications from rapid correction. Am. J. Kidney Dis. Off. J. Natl. Kidney Found. 50,673–680 (2007).
  3. Shalin R. Sanghvi, Paul S. Kellerman, Lisa Nanovic. Beer Potomania: An Unusual Cause of Hyponatremia at High Risk of Complications From Rapid Correction. AJKD. October 2007 Volume 50, Issue 4, Pages 673–68
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

Published by
Dr. C Humphreys

Recent Posts

Nocturia and OSA: Mechanism

Nocturia is a common symptom associated with obstructive sleep apnea. [1] Img Cred: Am J…

8 months ago

ASD vs. VSD Murmur Difference

ASD (Atrial Septal Defect) Wide, Fixed split S2 (in contrast to the normal variation in…

8 months ago

Mechanism of a Mixed Apnea

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

2 years ago

How Does Hypothyroidism Cause Hypoventilation?

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

2 years 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…

2 years ago

What is Peribronchovascular Distribution on CT imaging?

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

3 years ago

This website uses cookies.