Many disorders can cause ascites, but the most common is high blood pressure in the veins that bring blood to the liver (portal hypertension Portal Hypertension Portal hypertension is abnormally high blood pressure in the portal vein (the large vein that brings blood from the intestine to the liver) and its branches. Cirrhosis (scarring that distorts... read more ), which is usually due to cirrhosis Cirrhosis of the Liver Cirrhosis is the widespread distortion of the liver's internal structure that occurs when a large amount of normal liver tissue is permanently replaced with nonfunctioning scar tissue. The scar... read more .
If large amounts of fluid accumulate, the abdomen becomes very large, sometimes making people lose their appetite and feel short of breath and uncomfortable.
Analysis of the fluid can help determine the cause.
Usually, a low-sodium diet and diuretics can help eliminate excess fluid.
(See also Overview of Liver Disease Overview of Liver Disease Liver disease can manifest in many different ways. Characteristic manifestations include Jaundice (a yellowish discoloration of the skin and whites of the eyes) Cholestasis (reduction or stoppage... read more .)
Causes of Ascites
The most common cause of ascites is
Less common causes of ascites include disorders unrelated to the liver, such as cancer, heart failure Heart Failure (HF) Heart failure is a disorder in which the heart is unable to keep up with the demands of the body, leading to reduced blood flow, back-up (congestion) of blood in the veins and lungs, and/or... read more , kidney failure Chronic Kidney Disease Chronic kidney disease is a slowly progressive (months to years) decline in the kidneys’ ability to filter metabolic waste products from the blood. Major causes are diabetes and high blood pressure... read more , inflammation of the pancreas (pancreatitis Overview of Pancreatitis Pancreatitis is inflammation of the pancreas. The pancreas is a leaf-shaped organ about 5 inches (about 13 centimeters) long. It is surrounded by the lower edge of the stomach and the first... read more ), and tuberculosis Tuberculosis (TB) Tuberculosis is a chronic contagious infection caused by the airborne bacteria Mycobacterium tuberculosis. It usually affects the lungs. Tuberculosis is spread mainly when people breathe air... read more affecting the lining of the abdomen.
Ascites tends to occur in long-standing (chronic) rather than in short-lived (acute) liver disorders. It most commonly results from
Portal hypertension Portal Hypertension Portal hypertension is abnormally high blood pressure in the portal vein (the large vein that brings blood from the intestine to the liver) and its branches. Cirrhosis (scarring that distorts... read more —high blood pressure in the portal vein (the large vein that brings blood from the intestine to the liver) and its branches
Portal hypertension usually results from cirrhosis Cirrhosis of the Liver Cirrhosis is the widespread distortion of the liver's internal structure that occurs when a large amount of normal liver tissue is permanently replaced with nonfunctioning scar tissue. The scar... read more (severe scarring of the liver), which is most commonly caused by consumption of large amounts of alcohol, by fatty liver Fatty Liver Fatty liver is an abnormal accumulation of certain fats (triglycerides) inside liver cells. People with fatty liver may feel tired or have mild abdominal discomfort but otherwise have no symptoms... read more , or by viral hepatitis.
Ascites may occur in other liver disorders, such as severe alcoholic hepatitis without cirrhosis, chronic hepatitis, and obstruction of the hepatic vein (Budd-Chiari syndrome Budd-Chiari Syndrome Budd-Chiari syndrome is caused by blood clots that completely or partially block blood flow from the liver. The blockage may occur anywhere from the small and large veins that carry blood from... read more ).
In people with a liver disorder, ascitic fluid leaks from the surface of the liver and intestine and accumulates within the abdomen. A combination of factors is responsible. They include the following:
Fluid retention by the kidneys
Alterations in various hormones and chemicals that regulate body fluids
Also, albumin usually leaks from blood vessels into the abdomen. Normally, albumin, the main protein in blood, helps keep fluid from leaking out of blood vessels. When albumin leaks out of blood vessels, fluid also leaks out.
Symptoms of Ascites
Small amounts of fluid within the abdomen usually cause no symptoms. Moderate amounts may increase the person's waist size and cause weight gain. Massive amounts may cause abdominal swelling (distention) and discomfort. The abdomen feels taut, and the navel is flat or even pushed out.
The swollen abdomen puts pressure on the stomach, sometimes leading to loss of appetite, and pressure on the lungs, sometimes leading to shortness of breath.
In some people with ascites, the ankles swell because excess fluid accumulates there (causing edema Swelling Swelling is due to excess fluid in the tissues. The fluid is predominantly water. Swelling may be widespread or confined to a single limb or part of a limb. Swelling is often in the feet and... read more ).
Complications of ascites
Spontaneous bacterial peritonitis (infection of the ascitic fluid that develops for no apparent reason) sometimes occurs. This infection is common among people with ascites and cirrhosis Cirrhosis of the Liver Cirrhosis is the widespread distortion of the liver's internal structure that occurs when a large amount of normal liver tissue is permanently replaced with nonfunctioning scar tissue. The scar... read more , especially alcoholics.
If spontaneous bacterial peritonitis develops, people usually have abdominal discomfort, and the abdomen may feel tender. People may have a fever and feel generally unwell. They may become confused, disoriented, and drowsy. Untreated, this infection can be fatal. Survival depends on early treatment with appropriate antibiotics.
Diagnosis of Ascites
A doctor's evaluation
Sometimes an imaging test such as ultrasonography
Sometimes analysis of ascitic fluid
When a doctor taps (percusses) the abdomen, the fluid makes a dull sound. If the person's abdomen is swollen because the intestines are distended with gas, the tapping makes a hollow sound. However, a doctor may not be able to detect ascitic fluid unless the volume is about a quart or more.
If doctors are uncertain whether ascites is present or what is causing it, they may do ultrasonography or computed tomography (CT; see Imaging Tests of the Liver and Gallbladder Imaging Tests of the Liver and Gallbladder Imaging tests of the liver, gallbladder, and biliary tract include ultrasonography, radionuclide scanning, computed tomography (CT), magnetic resonance imaging (MRI), endoscopic retrograde cholangiopancreatography... read more ). In addition, a small sample of ascitic fluid can be withdrawn by inserting a needle through the wall of the abdomen—a procedure called diagnostic paracentesis Paracentesis Paracentesis is the insertion of a needle into the abdominal cavity for the removal of fluid. Normally, the abdominal cavity contains only a small amount of fluid. However, fluid can accumulate... read more . Laboratory analysis of the fluid can help determine the cause.
Treatment of Ascites
A low-sodium diet
Removal of ascitic fluid (therapeutic paracentesis)
Sometimes surgery to reroute blood flow (portosystemic shunting) or liver transplantation
For spontaneous bacterial peritonitis, antibiotics
The basic treatment for ascites is a low-sodium diet with a goal of 2,000 mg or less of sodium per day.
If diet is ineffective, people are usually also given drugs called diuretics (such as spironolactone or furosemide). Diuretics make the kidneys excrete more sodium and water into the urine so people urinate more.
If ascites becomes uncomfortable or makes breathing or eating difficult, the fluid may be removed through a needle inserted into the abdomen—a procedure called therapeutic paracentesis. The fluid tends to reaccumulate unless people also follow a low-sodium diet and take a diuretic. Because a large amount of albumin is usually lost from the blood into the abdominal fluid, albumin may be given intravenously.
If large amounts of fluid accumulate frequently or if other treatments are ineffective, a portosystemic shunt or liver transplantation Liver Transplantation Liver transplantation is the surgical removal of a healthy liver or sometimes a part of a liver from a living person and then its transfer into a person whose liver no longer functions. (See... read more may be needed. The portosystemic shunt Portosystemic shunting Portal hypertension is abnormally high blood pressure in the portal vein (the large vein that brings blood from the intestine to the liver) and its branches. Cirrhosis (scarring that distorts... read more connects the portal vein or one of its branches with a vein in the general circulation and thus bypasses the liver. However, placement of the shunt is an invasive procedure and can cause problems, such as deterioration of brain function (hepatic encephalopathy Hepatic Encephalopathy Hepatic encephalopathy is deterioration of brain function that occurs in people with severe liver disease because toxic substances normally removed by the liver build up in the blood and reach... read more ) and deterioration of liver function.
If spontaneous bacterial peritonitis is diagnosed, people are given antibiotics such as cefotaxime. Because this infection often recurs within a year, a different antibiotic (such as norfloxacin) is given after the initial infection resolves to prevent the infection from recurring.