Ascites

Overview, Causes, & Risk Factors

Ascites is the abnormal accumulation of fluid within the abdominal cavity. It is a condition with a wide range of causes. Ascites develops most frequently as a result of liver disease. It can also be seen in people who have cancer, kidney disease, and heart disease. Ascites is seen in people with pancreatic disease, as well as other conditions.

What is going on in the body?

Mechanisms in the body leading to ascites are complex and not completely understood.

The accumulation of fluid in the abdominal cavity can be associated with portal hypertension. This means there is an increased blood pressure in the veins draining the liver. The higher pressure can be caused by liver damage. It can also be caused by impaired drainage in the lymph system. This system takes excess fluid and particles away from the liver.

Low levels of albumin and other proteins in the blood also contribute to ascites. The force that holds plasma water within the blood vessels is reduced. Plasma water is lost into the abdominal cavity. Albumin in the ascitic fluid pulls yet more fluid across into this cavity.

Blood flow to the kidneys might be reduced. This leads to increased secretion of the hormone aldosterone. This increase causes the kidneys to retain salt and water. Urinary output is decreased, and fluid is retained. In some cases, kidney disease contributes to impaired elimination of salt and water.

Fluid may leak from capillaries, the pancreas, or the lymph system. Capillary fluid leakage can be caused by inflammation or infection.

All of these events may lead to a large volume of abdominal ascites. Adults with cirrhosis of the liver may have as much as 10 to 12 liters of fluid in their abdominal cavities.

What are the causes and risks of the condition?

Ascites is most often a result of liver disease, including the following:

alcoholic liver disease

chronic hepatitis

cirrhosis, which is permanent scarring of the liver

liver cancer

sudden liver failure, which can be due to infection or drug reactions

Other common causes of ascites include the following:

bile leaking into the abdomen

blood or fluid leaking from the blood vessels into the abdomen

cancer

certain kidney conditions

congestive heart failure, a condition in which the weakened heart fails to pump blood effectively

constrictive pericarditis, which is a tightening of the lining around the heart

gastrointestinal diseases that cause a loss of protein, such as inflammatory bowel disease

inflammation of the lining of the abdomen, known as peritonitis

obstruction in the inferior vena cava, one of the largest veins in the body

pancreatic fluid leaking into the abdomen

severe malnutrition

tuberculosis that has infected the peritoneum

tumors on the lining of the abdomen

Symptoms & Signs

What are the signs and symptoms of the condition?

Depending on the amount of ascites and the cause, there may be no symptoms at all. Following are some of the common symptoms:

abdominal pain

changes in bowel function

difficulty breathing, especially when trying to take deep breaths

difficulty walking

fatigue

feeling full after eating only small amounts of food

increasing abdominal girth

low back pain

shortness of breath

Diagnosis & Tests

How is the condition diagnosed?

The diagnosis of ascites begins with a medical history and physical exam. The healthcare provider may be able to detect fluid in the abdomen. Special X-ray tests are also commonly used to diagnose ascites and help determine the cause.

A diagnostic test, called paracentesis, may be done. This involves the insertion of a needle through the skin and into the abdominal cavity. The needle is used to withdraw fluid. Testing the fluid helps to determine the cause of the ascites. For example, an elevated white blood cell count, or WBC, may indicate an infection.

Prevention & Expectations

What can be done to prevent the condition?

Some cases of ascites can be prevented. For example, cirrhosis can be prevented by drinking alcohol only in moderation. Effective treatment of congestive heart failure can prevent ascites from that cause.

What are the long-term effects of the condition?

Long-term effects of ascites can include the following:

difficulty breathing

difficulty walking and performing daily activities

gastrointestinal problems

heart failure

kidney failure

malnutrition

sleep disorders

What are the risks to others?

Ascites is not contagious and poses no risk to others.

Treatment & Monitoring

What are the treatments for the condition?

Treatment of ascites includes treatment of the underlying disorder. Some of the general treatment guidelines followed for ascites itself are as follows:

bed rest to improve kidney function

a diet limited to 2 grams of sodium a day

fluid restricted to 1 liter a day

hospitalization to monitor the daily weight and salt balance

Diuretics, also called water pills, may also be used to treat ascites. These medications help the body excrete extra water through the kidneys. Common diuretics include spironolactone, amiloride, and triamterene. If these are not effective, stronger diuretics may be used. These stronger medicines include furosemide, thiazide, and ethacrynic acid.

Some people with massive ascites may need a paracentesis to remove excess fluid. A needle is inserted into the abdominal cavity, and extra fluid is drained out.

Most people respond to these measures. About 10% to 15% are resistant and require other methods to control the ascites.

Other individuals may need a transjugular intrahepatic portosystemic shunt, also called TIPS. This is a mesh tube that is passed through the skin of the neck and into the jugular vein. The tube is then advanced into the liver. It is pushed into the portal vein, which drains into the liver. The shunt reduces pressure and ascites formation.

In rare and selected cases, a liver transplant may be needed.

What are the side effects of the treatments?

Side effects of diuretics can include the following:

dehydration

high or low potassium levels in the blood

kidney failure

Removal of large volumes of fluid using parencentesis may cause the following conditions:

decreased kidney function

low blood pressure, called hypotension

shock

Following are some of the side effects that shunting procedures can cause:

abnormal blood clotting that may result in bleeding

change in mental functioning or level of consciousness

clotting of the shunt

infection

What happens after treatment for the condition?

In most cases, treatment of ascites is lifelong.

How is the condition monitored?

Ascites will be monitored with lab tests and regular visits to the healthcare provider. Any new or worsening symptoms should be reported to the provider.