What causes abdominal swelling?

A swollen abdomen may feel tight, heavy or visibly enlarged. Digestive causes include trapped gas, constipation and food intolerance. Fluid can collect in the abdomen when liver disease affects fluid balance, or when cancer irritates the lining of the abdomen. A growing mass can also change the shape of the abdomen. Ovarian cancer and primary peritoneal cancer may present with abdominal swelling; malignant ascites refers to cancer-related fluid in the abdomen. In children, neuroblastoma or Wilms tumour can cause an abdominal mass. These conditions are possible explanations, not conclusions from the symptom alone.

Notice when the swelling began, whether it changes after eating or passing stool, and whether your weight, appetite or bowel habits have changed. Arrange a clinical assessment if it persists, returns, becomes uncomfortable, or comes with unexplained weight loss. A clinician may examine the abdomen and decide whether blood tests or imaging are appropriate. Do not start laxatives or restrictive diets repeatedly without understanding the cause.

Seek urgent medical help for severe or rapidly worsening pain, repeated vomiting, a very hard abdomen, inability to pass stool or gas, fainting, or difficulty breathing. Contact a clinician promptly if swelling is accompanied by yellowing of the skin, blood in stool, persistent fever, or a new abdominal lump.

What findings could explain my swelling? Could fluid, constipation or an organ problem be involved? Do I need an abdominal examination, blood tests or imaging? Which changes should prompt urgent review?