Differential Diagnosis of RUQ Pain
The differential diagnosis of right upper quadrant (RUQ) pain can be extensive, involving various organs and systems. Here's a categorized approach to help in diagnosing the cause of RUQ pain:
Single Most Likely Diagnosis
- Gallbladder Disease (Cholecystitis or Cholelithiasis): This is often the most common cause of RUQ pain, especially in females over 40 years old. The pain is typically constant, severe, and may radiate to the right shoulder or back, accompanied by nausea, vomiting, and fever.
Other Likely Diagnoses
- Peptic Ulcer Disease: Gastric or duodenal ulcers can cause RUQ pain, often described as burning or gnawing, and may be related to food intake.
- Hepatitis: Inflammation of the liver can cause RUQ pain, jaundice, and elevated liver enzymes.
- Pyelonephritis or Kidney Stones: While these conditions primarily affect the flank, they can sometimes radiate pain to the RUQ.
- Pneumonia (Right Lower Lobe): Basilar pneumonias can cause referred pain to the RUQ due to the shared innervation of the diaphragm.
Do Not Miss Diagnoses
- Appendicitis (with an Atypical Presentation): Although appendicitis typically presents with right lower quadrant pain, an atypically located appendix can cause RUQ pain.
- Myocardial Infarction: Cardiac ischemia can sometimes present with atypical pain patterns, including RUQ pain, especially in women or diabetic patients.
- Pulmonary Embolism: A large pulmonary embolism can cause sudden onset of chest pain and RUQ pain due to referred pain from the diaphragm.
- Aortic Dissection: This is a medical emergency that can present with severe, tearing chest pain radiating to the back and potentially causing RUQ pain.
Rare Diagnoses
- Hepatic Abscess or Cyst: These conditions can cause RUQ pain, fever, and jaundice, but are less common.
- Right Adrenal Gland Pathology (e.g., Adrenal Hemorrhage): Rarely, pathology in the right adrenal gland can cause RUQ pain.
- Intestinal Obstruction or Ischemia: These conditions can cause severe abdominal pain, including in the RUQ, but are less common causes of isolated RUQ pain.
- Diaphragmatic Disorders (e.g., Diaphragmatic Hernia): These can cause RUQ pain due to irritation of the diaphragm or referred pain.