Differential Diagnosis for Right-Sided Pain

The patient's complaint of pain on the right side for the past five days can be approached by considering various potential causes, categorized for clarity and urgency.

• Single Most Likely Diagnosis

  • Musculoskeletal strain: This is often the most common cause of acute onset pain, especially if the patient has recently engaged in unusual physical activity or has a history of similar episodes. The pain is typically localized and may be exacerbated by movement.

• Other Likely Diagnoses

  • Urinary tract infection (UTI) or pyelonephritis: If the pain is localized to the flank or radiates to the groin, a UTI, especially involving the right kidney (pyelonephritis), should be considered. Symptoms might include dysuria, frequency, and fever.
  • Biliary colic or cholecystitis: Pain in the right upper quadrant could suggest a gallbladder issue, such as biliary colic from a gallstone or cholecystitis, an inflammation of the gallbladder. Nausea, vomiting, and fever may accompany the pain.
  • Hepatitis: Inflammation of the liver can cause right upper quadrant pain, and while less common, should be considered, especially with a history of liver disease, exposure to hepatitis viruses, or recent travel.

• Do Not Miss Diagnoses

  • Appendicitis: Although classically presenting with pain that migrates to the right lower quadrant, appendicitis can sometimes present atypically, especially in retrocecal appendicitis. It's crucial to consider this diagnosis due to the potential for severe consequences if missed.
  • Pulmonary embolism: If the pain is pleuritic (sharp and worsens with deep breathing), a pulmonary embolism should be considered, particularly in patients with risk factors such as recent immobilization, cancer, or history of deep vein thrombosis.
  • Ectopic pregnancy: In women of childbearing age, an ectopic pregnancy can present with abdominal pain and must be ruled out due to its potential for severe morbidity and mortality.

• Rare Diagnoses

  • Right-sided diverticulitis: While more common on the left, diverticulitis can occur on the right side, especially in certain populations like those of Asian descent.
  • Intestinal obstruction: This could cause severe abdominal pain and is a surgical emergency. It might be considered if there's a history of abdominal surgery or other risk factors.
  • Pneumonia: If the pain is pleuritic and accompanied by respiratory symptoms such as cough or fever, pneumonia should be considered, especially in vulnerable populations like the elderly or those with compromised immune systems.