MedSchool: Ace Your OSCEsThe Medical Company
GET - On the App Store
Gastro Exam


November 26th, 2019


Ascites (fluid within the peritoneal cavity) may be caused by many conditions - particularly cirrhosis, heart failure and hypoalbuminaemia. Ascites can be difficult to diagnose on examination, however shifting dullness and the fluid wave can assist in assessing for abdominal fluid.
  • Causes of Ascites

  • Cirrhosis
  • Heart failure
  • Constrictive pericarditis
  • Peritonitis - tuberculous, neoplasmic, bacterial
  • Hypoalbuminaemia - nephrotic syndrome, malnutrition
  • Pancreatitis
  • Cancer - liver, stomach, pancreas, adrenals, gut
  • Thrombosis - portal vein, mesenteric vessels
  • Ovarian disease
  • Hypothyroidism
  • Dialysis

Shifting Dullness

  • How to Elicit

  • Percuss the patient's abdomen from the umbilicus to the left flank, noting where the percussion note changes from resonant to dull. Ask the patient to roll over to their left side and repeat percussion. 
  • Interpretation

  • If ascites is present the area of resonance will move at least 3cm medially.

Fluid Wave

  • How to Elicit

  • Ask the patient or an assistant to apply pressure using the ulnar surface of their hand to the midline of the abdomen. Place the fingertips of one hand along the left flank and with the other hand firmly palpate the opposite flank.
  • Interpretation

  • Ascites is present if a fluid wave is felt on the opposite side of the abdomen.


  • Note

  • Both shifting dullness and fluid wave have poor sensitivity and specificity for the assessment of ascites.
Next Page
Want more info like this?
  • Your electronic clinical medicine handbook
  • Guides to help pass your exams
  • Tools every medical student needs
  • Quick diagrams to have the answers, fast
  • Quizzes to test your knowledge
Sign Up Now

Snapshot: Initialising...