Differential Diagnosis for Lower Abdominal Pain
Single Most Likely Diagnosis
- Appendicitis: This is often the first consideration for lower abdominal pain, especially if the pain is localized to the right lower quadrant. The justification for this diagnosis is the high prevalence of appendicitis in patients presenting with acute lower abdominal pain.
Other Likely Diagnoses
- Urinary Tract Infection (UTI): A common cause of lower abdominal pain, especially in women. The presence of dysuria, frequency, and urgency supports this diagnosis.
- Ovarian Cyst: These can cause intermittent or constant lower abdominal pain, often related to menstrual cycles in women of reproductive age.
- Diverticulitis: Inflammation of a diverticulum in the colon, which can cause left lower quadrant pain, especially in older adults.
- Inflammatory Bowel Disease (IBD): Conditions like Crohn's disease and ulcerative colitis can cause chronic lower abdominal pain, often accompanied by changes in bowel habits and weight loss.
Do Not Miss Diagnoses
- Ectopic Pregnancy: A life-threatening condition that must be considered in any woman of childbearing age presenting with lower abdominal pain, especially if there's a history of missed periods or positive pregnancy test.
- Ruptured Aneurysm: Although rare, a ruptured abdominal aortic aneurysm can present with severe lower abdominal or back pain and is immediately life-threatening.
- Ovarian Torsion: A gynecological emergency that causes severe, sudden onset of lower abdominal pain, often accompanied by nausea and vomiting.
- Intestinal Obstruction: Can cause severe abdominal pain, vomiting, and constipation, requiring prompt surgical intervention.
Rare Diagnoses
- Endometriosis: While not rare, it's less commonly considered in the acute setting but can cause chronic lower abdominal pain related to menstrual cycles.
- Lymphoma: Abdominal lymphoma can cause lower abdominal pain due to lymph node enlargement or intestinal involvement.
- Tuberculosis: Can cause chronic lower abdominal pain, especially in immunocompromised patients or those from endemic areas.
- Malrotation with Volvulus: A rare condition where the intestine twists, cutting off its blood supply, and can cause severe abdominal pain, often in children but can occur at any age.