R18: Ascites

Fluid has built up in your abdomen.

The abdominal organs are located in the abdomen. The abdomen is lined from within with a membrane. The membrane is made up of individual cells. These cells normally release a small amount of fluid into the abdomen. Thanks to this fluid, the organs can move and slide past each other.

Too much fluid has accumulated around the organs in your abdomen. There are various reasons for this. The fluid can build up when the liver is inflamed or scarred. Altered cells in the abdomen can also lead to too much fluid building up.

Fluid building up in the abdominal cavity usually results in the abdomen being thicker than normal. You may also have a feeling of pressure in your abdomen.

Additional indicator

On medical documents, the ICD code is often appended by letters that indicate the diagnostic certainty or the affected side of the body.

  • G: Confirmed diagnosis
  • V: Tentative diagnosis
  • Z: Condition after
  • A: Excluded diagnosis
  • L: Left
  • R: Right
  • B: Both sides

Further information


This information is not intended for self-diagnosis and does not replace professional medical advice from a doctor. If you find an ICD code on a personal medical document, please also note the additional indicator used for diagnostic confidence.
Your doctor will assist you with any health-related questions and explain the ICD diagnosis code to you in a direct consultation if necessary.


Provided by the non-profit organization “Was hab’ ich?” gemeinnützige GmbH on behalf of the Federal Ministry of Health (BMG).