What are the risk factors for malignant ascites?

Cancer cells can irritate or spread across the lining of the abdomen, making it leak fluid or preventing normal absorption. A tumour may also obstruct lymphatic channels. When cancer affects the liver, changes in blood flow and protein balance can encourage fluid to move into the abdominal space.

Ovarian cancer and primary peritoneal cancer are recognised causes. Other cancers can also lead to malignant ascites when they involve abdominal organs or the peritoneum. Fluid in the abdomen is not automatically malignant; infection, liver disease, heart conditions, and other problems can cause similar swelling.

Tell your oncology team about increasing abdominal size, pressure, early fullness after eating, nausea, or breathlessness. Assessment may include an examination and imaging, with fluid testing when needed. Treatment focuses on the underlying cancer and relieving pressure or discomfort.

Seek urgent medical help for severe or rapidly worsening breathlessness, intense abdominal pain, repeated vomiting, confusion, fainting, or inability to pass urine. Contact your team promptly if the abdomen becomes quickly more swollen or eating and drinking become difficult.

Ask what may be causing the fluid, whether testing is needed, and how the result would change treatment. Ask how symptoms can be relieved, what signs suggest infection or bowel pressure, and whom to contact outside clinic hours.