Undrained ascites doesn’t just sit harmlessly in the abdomen. As fluid accumulates, it compresses surrounding organs, raises the risk of serious infections, and accelerates kidney failure. For patients with refractory ascites (fluid that no longer responds to diuretics), survival drops to about 50% at six months and 25% at one year. The complications build on each other, and many of them are preventable with timely drainage.
Breathing Gets Progressively Harder
The most immediately noticeable effect of undrained ascites is difficulty breathing. Liters of fluid push the diaphragm upward into the chest cavity, physically limiting how much the lungs can expand. The diaphragm still contracts, but its ability to pull air into the lungs is significantly reduced. As the volume of fluid grows, the diaphragm flattens and its radius of curvature increases, weakening its pumping action even further.
Your body tries to compensate. The muscles between your ribs work harder to lift the rib cage and pull in air, but this only partially makes up for the diaphragm’s lost function. Tidal volume (the amount of air you take in with each breath) drops, and carbon dioxide levels in the blood rise. In some cases, fluid migrates through small defects in the diaphragm and collects around the lungs, a condition called hepatic hydrothorax. At that point, breathing becomes difficult even at rest.
Infection Risk Climbs Sharply
Ascitic fluid is a breeding ground for bacteria. Spontaneous bacterial peritonitis, or SBP, occurs when bacteria from the gut cross into the abdominal fluid without any obvious source like a ruptured organ. Symptoms include fever, abdominal pain, and confusion, though some patients develop SBP with no obvious warning signs at all.
The risk is highest in people with advanced liver disease. One study found that patients with severe liver dysfunction and low-protein ascites had a 61% chance of developing SBP within one year without preventive treatment. SBP is dangerous on its own, but it also triggers a cascade: it is one of the most common precipitating factors for hepatorenal syndrome, a form of kidney failure that carries its own high mortality rate.
Kidneys Begin to Fail
The connection between undrained ascites and kidney failure is direct. In cirrhosis, the blood vessels supplying the gut and the rest of the body dilate abnormally, which drops overall blood pressure. The body responds by activating stress hormones that constrict blood vessels in the kidneys to try to maintain pressure elsewhere. As liver disease worsens, cardiac output falls further, and the kidneys receive less and less blood flow.
This process, called hepatorenal syndrome, essentially starves the kidneys of oxygen. The kidneys themselves are structurally normal at first, but they stop filtering waste because they aren’t getting enough blood. Three of the most common triggers for this syndrome are SBP, gastrointestinal bleeding, and draining large volumes of ascites without replacing albumin (a protein that helps maintain blood volume). Leaving ascites undrained doesn’t avoid this risk. It raises it, because the untreated fluid increases the likelihood of SBP, which then triggers kidney failure.
The Abdominal Wall Weakens
Persistent pressure from ascites stretches the abdominal wall, and umbilical hernias are common in cirrhotic patients with significant fluid. The real danger comes when a hernia ruptures spontaneously, allowing ascitic fluid to leak through the skin. This complication carries a mortality rate close to 30%. In rare cases, abdominal contents can push through the weakened tissue, a surgical emergency called evisceration. Hernias that become incarcerated (trapped and unable to be pushed back in) also require urgent repair, which is far riskier in a patient with advanced liver disease.
Circulation and Heart Function Suffer
A large volume of fluid in the abdomen compresses the inferior vena cava, the major vein that returns blood from the lower body to the heart. This reduces venous return, which means the heart has less blood to pump with each beat. The body compensates with a faster heart rate, but this is an inefficient workaround. Blood pools in the lower extremities, causing swelling in the legs and feet. Reduced blood return also lowers oxygen delivery throughout the body, which can cause lightheadedness, fatigue, and in severe cases, altered mental status.
Nutrition Deteriorates Quickly
Ascites physically compresses the stomach, reducing how much food you can eat at one sitting. Early fullness, nausea, and changes in taste are common. Over time, this leads to significant malnutrition and muscle wasting (sarcopenia), which further weakens the body’s ability to recover from any of the other complications on this list.
The relationship runs in both directions. Malnutrition accelerates the progression of liver disease, which produces more ascites, which makes it even harder to eat. Inflammatory compounds in the blood, bacterial overgrowth in the small intestine, and the sheer pressure of abdominal fluid all contribute to this cycle. Calculating a patient’s actual nutritional needs is complicated by the fluid itself, since the weight of ascites can mask how much muscle and fat the person has actually lost.
Daily Life Becomes Severely Limited
Beyond the medical risks, undrained ascites makes basic activities difficult. Moving around becomes uncomfortable or painful. Sleeping is disrupted because lying flat worsens the pressure on the diaphragm. Eating, drinking, and breathing all become harder as fluid volume increases. Many patients describe feeling trapped in their own body, unable to do things they managed weeks or months earlier.
When Drainage Is Recommended
Clinical guidelines from the American Association for the Study of Liver Diseases grade ascites on a three-tier scale. Grade 1 (detectable only on imaging) typically requires no treatment. Grade 2 (moderate, visible swelling) is managed with a low-sodium diet and diuretics. Grade 3 (large-volume, tense ascites) calls for therapeutic drainage, a procedure called large-volume paracentesis, defined as removing 5 liters or more of fluid. There is no upper limit on how much can be drained in a single session, as long as albumin is infused to maintain blood volume.
Refractory ascites, fluid that returns quickly despite maximum diuretic therapy, represents the most serious category. At this stage, repeated drainage becomes a regular part of life, and evaluation for a liver transplant is typically the next step. The survival statistics for refractory ascites are sobering: without transplant, three out of four patients do not survive beyond one year. Timely, repeated drainage won’t cure the underlying liver disease, but it prevents many of the complications described above and preserves quality of life while other options are explored.