What Causes Alcohol-Related Ascites?

Pathophysiology is awesome. In an attempt to try to remember some of the conditions that are of greater interest to me, or that I have actually seen, I decided to write some blog posts about them. Number 1: ascites related to alcoholism. This isn’t of particular personal importance to me, but I do remember seeing a number of people (mostly all men) in Nepal and India who were plagued with *incredibly* large bellies when compared with the rest of their bodies, which were very thin. These people were especially centered in Kathmandu, but some in villages as well. My guess for what caused this was alcohol-related ascites, or perhaps metabolic syndrome. Or both. For now, though, this is what causes alcohol-related ascites.

Ascites is the accumulation of excess fluid within the peritoneal cavity, where all of the abdominal organs are located. Normally, there should be no excess fluid in the cavity. So why does ascites occur? Extreme alcoholism causes a liver disease called cirrhosis, which is fibrosis, or scaring, of the liver tissue. The liver is the “detoxifier” of toxins in the body and alcohol is a toxin. So, if there is a constant stream of alcohol running through the body the functional units of the liver, lobules, (made of hepatocytes) will become over-worked, damaged and scarred. There are three stages of alcohol-related liver disease: 1) alcoholic fatty liver, 2) alcoholic hepatitis, and 3) alcoholic cirrhosis. Once you get to stage two, the damage becomes irreparable.

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So the liver has stopped working. How does ascites happen? The liver produces, among other important things, plasma proteins including albumin. Albumin is key to maintaining colloid osmotic pressure. This means that albumin binds water and other cations to ensure that they stay in the blood instead of in the interstitial fluids and tissues. If liver function is impaired and it ceases to produce enough albumin, colloid osmotic pressure will decrease. When colloid osmotic pressure decreases, normal blood homeostasis cannot be contained because albumin isn’t circulating in the plasma and holding on to the water. Instead, the water stays in the peritoneal cavity and builds up, which is ascites.