Abdominal aortic aneurysm differential diagnosis

Jump to navigation Jump to search

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor-In-Chief: Cafer Zorkun, M.D., Ph.D. [2]; Hardik Patel, M.D. Ramyar Ghandriz MD[3]


An abdominal aortic aneurysm should be differentiated from other causes of abdominal pain such as acute cholecystitis, gastrointestinal bleeding, perforated peptic ulcer, ischemic bowel, nephrolithiasis, pyelonephritis, appendicitis, cholelithiasis, large bowel obstruction, small bowel obstruction, pancreatitis, musculoskeletal pain, myocardial infarction, and urinary tract infection.

Differentiating Abdominal Aortic Aneurysm from other Diseases

  • A patient becomes symptomatically after abdominal aortic rupture, so the differentiation is according to the rupture which causes acute abdomen signs and symptoms.
  • Non-symptomatic AAA is diagnosed through abdominal ultrasound with no other differentials.
  • In a patient with a suspected abdominal aortic aneurysm, the following conditions also need to be considered:[1]
Classification of acute abdomen based

on etiology

Presentation Clinical findings Diagnosis Comments
Fever Rigors and Chills Abdominal Pain Jaundice Hypotension Guarding Rebound Tenderness Bowel sounds Lab Findings Imaging
Common causes of


Spontaneous bacterial peritonitis + Diffuse Hypoactive
  • Ascitic fluid PMN>250 cells/mm³
  • Culture: Positive for single organism
Ultrasound for evaluation of liver cirrhosis -
Perforated gastric and duodenal ulcer + Diffuse + + + N
  • Ascitic fluid
    • LDH > serum LDH
    • Glucose < 50mg/dl
    • Total protein > 1g/dl
Air under diaphragm in upright CXR Upper GI endoscopy for diagnosis
Acute suppurative cholangitis + + RUQ + + + + ±
Acute cholangitis + RUQ + N Abnormal LFT Ultrasound shows biliary dilatation Biliary drainage (ERCP) + IV antibiotics
Acute cholecystitis + RUQ + Hypoactive Ultrasound shows gallstone and evidence of inflammation Murphy’s sign
Acute pancreatitis + Epigastric ± N Increased amylase / lipase Ultrasound shows evidence of inflammation Pain radiation to back
Acute appendicitis + RLQ + + Hypoactive Leukocytosis Ultrasound shows evidence of inflammation Nausea & vomiting, decreased appetite
Acute diverticulitis + LLQ ± + Hypoactive Leukocytosis CT scan and ultrasound shows evidence of inflammation
Hollow Viscous Obstruction Small intestine obstruction Diffuse + ± Hyperactive then absent Leukocytosis Abdominal X ray Nausea & vomiting associated with constipation, abdominal distention
Gall stone disease/Cholelithiasis ±
Volvulus - Diffuse - + - Hypoactive Leukocytosis CT scan and abdominal X ray Nausea & vomiting associated with constipation, abdominal distention
Biliary colic - RUQ + - - N Increased bilirubin and alkaline phosphatase Ultrasound Nausea & vomiting
Renal colic - Flank pain - - - N Hematuria CT scan and ultrasound Colicky abdominal pain associated with nausea & vomiting
Vascular Disorders Ischemic causes Mesenteric ischemia ± Periumbilical - - - Hyperactive Leukocytosis and lactic acidosis CT scan Nausea & vomiting, normal physical examination
Acute ischemic colitis ± Diffuse - + + Hyperactive then absent Leukocytosis CT scan Nausea & vomiting
Hemorrhagic causes Ruptured abdominal aortic aneurysm - Diffuse - - - N Normal CT scan Unstable hemodynamics
Intra-abdominal or retroperitoneal hemorrhage - Diffuse - - - N Anemia CT scan History of trauma
Gynaecological Causes Fallopian tube Acute salpingitis + LLQ/ RLQ ± ± N Leukocytosis Pelvic ultrasound Vaginal discharge
Ovarian cyst complications and endometrial disease Torsion of the cyst - RLQ / LLQ - ± ± N Increased ESR and CRP Ultrasound Sudden onset severe pain with nausea and vomiting
Endometriosis - RLQ/LLQ - +/- +/- N Normal Laproscopy Menstrual-associated symptoms, pelvic


Cyst rupture - RLQ / LLQ - +/- +/- N Increased ESR and CRP Ultrasound Sudden onset severe pain with nausea and vomiting
Pregnancy Ruptured ectopic pregnancy - RLQ / LLQ - - - N Positive pregnancy test Ultrasound History of missed period and vaginal bleeding
Functional Irritable Bowel Syndrome - Diffuse - - - - N

Clinical diagnosis



  1. Kumar D (2018). "Complicated jejunal diverticulitis with unusual presentation". Radiol Case Rep. 13 (1): 58–64. doi:10.1016/j.radcr.2017.10.002. PMC 5826736. PMID 29487638.

Template:WH Template:WS CME Category::Cardiology