Ascites is the buildup of fluid in the abdominal cavity. Ascites caused by cancer is called malignant ascites and accounts for 10% of people with ascites. Malignant ascites appears most often in people with breast , colon , gastrointestinal tract (stomach  and intestines ), ovarian , pancreatic , and uterine  cancers.
Relieving side effects, also called symptom management, palliative care , or supportive care, is an important part of cancer care and treatment. Talk with your health care team about any symptoms of ascites that you experience, including any new symptoms or a change in symptoms.
Ascites often causes great discomfort. People with ascites may experience the following symptoms:
- Weight gain 
- Dyspnea 
- Abdominal swelling
- Sense of fullness or bloating
- Sense of heaviness
- Nausea or vomiting 
- Changes to the navel (belly button)
- Hemorrhoids (a condition that causes painful swelling near the anus)
- Ankle swelling
- Fatigue 
- Decreased appetite 
To diagnose ascites, the doctor may examine your abdominal area and ask you about any recent symptoms. The following tests may help diagnose ascites:
- X-ray (a picture of the inside of the body)
- Ultrasound  (an imaging test that uses sound waves to create a picture of the inside of the body)
- Computerized tomography (CT or CAT) scan  (an imaging test that creates a three-dimensional picture of the inside of the body with an x-ray machine)
- Paracentesis (the removal and analysis of fluid from the abdomen with a needle) may be performed after the fluid is discovered to find out what is causing it (for example, an infection, cancer, or another condition).
Management and treatment
The goal of treatment for ascites is to relieve your symptoms, such as shortness of breath, abdominal pain, fatigue, decreased appetite, feeling full after eating little food, or not being able to exercise. You may not need treatment if the ascites is not causing discomfort. Ascites treatment may have unpleasant side effects, so it is important to talk with your doctor about the risks and benefits of each option before deciding on a treatment plan.
The following tips may help relieve ascites:
- Reduce the amount of salt you eat, and don't drink as much water and other liquids as usual. However, many patients find this regimen unpleasant and difficult to follow.
- Take diuretics, which are medications that reduce the amount of water in the body. Although diuretics are effective and well tolerated in most people, they may cause unpleasant side effects in some people, including loss of sleep, skin problems, fatigue, low blood pressure, and problems with self-esteem. If ascites is causing respiratory (breathing) problems or the diuretic treatment stops working, your doctor may recommend paracentesis (see above). If frequent paracenteses are needed to control the fluid buildup, a member of your health care team may discuss placing a special catheter  (a small tube placed in the abdomen through the skin) for easy, frequent removal of fluid, even while you are at home.
- Chemotherapy (drugs used to kill cancer cells) is appropriate only for people with certain cancers, such as lymphoma or breast and ovarian cancers; however, chemotherapy is rarely used to manage ascites.
- Rarely, a person may need surgery. This involves placing a shunt (a device used to bypass or divert fluid from one place to another) or catheter to drain fluids from the abdomen.
LIVESTRONG - Ascites