Abdominal and flank pain are common complaints encountered by EMTs and paramedics in the field. These symptoms can arise from a wide range of underlying conditions, making it crucial for first responders to conduct a thorough assessment to prioritize care and transport decisions. This article outlines the differential diagnosis of abdominal and flank pain in adult patients, emphasizing the key considerations and steps in prehospital care.

Common Causes of Abdominal and Flank Pain

  1. Gastrointestinal Causes:
    • Appendicitis: Often presents with right lower quadrant pain, nausea, and sometimes fever. Pain typically starts around the navel and then shifts.
    • Gastroenteritis: Involves inflammation of the stomach and intestines, leading to cramping, diarrhea, vomiting, and often diffuse abdominal pain.
    • Peptic Ulcer Disease: Characterized by burning or gnawing pain in the upper abdomen, which may improve or worsen with eating.
  2. Genitourinary Causes:
    • Kidney Stones: Sharp, severe pain in the flank, radiating to the groin, often accompanied by hematuria (blood in urine) and sometimes nausea or vomiting.
    • Urinary Tract Infection (UTI): Lower abdominal pain, dysuria (painful urination), increased urinary frequency, and urgency.
    • Pyelonephritis: A type of kidney infection that can cause flank pain, fever, and urinary symptoms.
  3. Gynecological Causes (in women):
    • Ovarian Cysts: Sudden onset of sharp lower abdominal pain, often on one side, which can be intermittent.
    • Ectopic Pregnancy: Severe, sharp lower abdominal pain, often accompanied by vaginal bleeding and a missed menstrual period.
  4. Cardiovascular Causes:
    • Abdominal Aortic Aneurysm (AAA): Typically presents with sudden, severe abdominal or back pain, a pulsatile abdominal mass, and hypotension. This is a life-threatening condition requiring immediate transport.
    • Mesenteric Ischemia: Severe abdominal pain, out of proportion to physical findings, often in elderly patients with a history of cardiovascular disease.
  5. Musculoskeletal Causes:
    • Muscle Strain: Can cause localized pain in the abdominal or flank area, typically related to recent physical activity or trauma.
    • Herniated Disc: May present with flank or abdominal pain radiating from the back, often accompanied by neurological symptoms like numbness or weakness in the lower extremities.
  6. Other Causes:
    • Herpes Zoster (Shingles): Painful rash along a dermatomal distribution, often preceded by severe localized pain.
    • Diabetic Ketoacidosis (DKA): Abdominal pain, nausea, vomiting, and altered mental status in a diabetic patient.

Prehospital Assessment and Management

1. Patient History:

  • Onset and Duration: When did the pain start? Was it sudden or gradual?
  • Location and Radiation: Where is the pain located? Does it radiate anywhere?
  • Quality and Severity: How would the patient describe the pain (sharp, dull, burning)? Rate the pain on a scale of 1-10.
  • Associated Symptoms: Nausea, vomiting, fever, urinary symptoms, vaginal bleeding, etc.
  • Medical History: Any history of similar pain, chronic illnesses (e.g., diabetes, cardiovascular disease), recent surgeries, or trauma?
  • Medications: Current medications, including over-the-counter and herbal supplements.

2. Physical Examination:

  • Vital Signs: Assess for abnormalities such as tachycardia, hypotension, or fever.
  • Abdominal Examination: Look for signs of peritonitis (rebound tenderness, guarding), distension, or pulsatile masses.
  • Costovertebral Angle (CVA) Tenderness: Gently percuss the flank area to check for pain indicative of kidney pathology.
  • Skin Examination: Check for rashes or signs of trauma.

3. Immediate Management:

  • Pain Relief: Administer appropriate pain relief following local protocols (e.g., analgesics, antiemetics).
  • Fluid Resuscitation: For patients with signs of dehydration or shock, initiate intravenous fluids.
  • Positioning: Position the patient for comfort; often, patients with severe abdominal pain prefer lying still with their knees bent.
  • Monitoring: Continuously monitor vital signs, including heart rate, blood pressure, and oxygen saturation.

4. Transport Decisions:

  • Urgency: Patients with signs of shock, severe pain, or potential life-threatening conditions (e.g., AAA, ectopic pregnancy) require immediate transport to the nearest appropriate facility.
  • Destination: Consider the patient’s medical history and the suspected underlying cause when choosing the hospital. Some conditions may require specialized care available at certain centers.


Differential diagnosis of abdominal and flank pain in adult patients is a complex process requiring careful consideration of various potential causes. EMTs and paramedics play a crucial role in early identification and management of these conditions, ensuring timely and appropriate care. By maintaining a systematic approach to assessment and staying informed about the diverse etiologies of abdominal pain, first responders can improve patient outcomes in the prehospital setting.