Differential Diagnosis for Right Lower Abdominal Pain
The differential diagnosis for right lower abdominal pain can be categorized into several groups based on the likelihood and potential impact of missing the diagnosis.
Single Most Likely Diagnosis
- Appendicitis: This is the most common cause of right lower abdominal pain, especially if the pain is acute, severe, and accompanied by fever, nausea, and vomiting. The pain often starts near the navel and then moves to the right lower abdomen.
Other Likely Diagnoses
- Ovarian cyst or torsion: In females, ovarian cysts can cause right lower abdominal pain if they rupture or become twisted, cutting off their blood supply.
- Ectopic pregnancy: Another condition in females, where the embryo implants outside the uterus, often causing severe abdominal pain.
- Intestinal obstruction: Blockage of the intestine can cause severe abdominal pain, vomiting, and constipation.
- Inflammatory bowel disease (Crohn's disease or ulcerative colitis): Chronic conditions that cause inflammation and irritation in the digestive tract, leading to abdominal pain, diarrhea, and weight loss.
- Kidney stones: Small, hard mineral deposits that can cause severe pain if they become lodged in the urinary tract.
Do Not Miss Diagnoses
- Ruptured abdominal aortic aneurysm: A life-threatening condition where the aorta ruptures, causing severe abdominal pain and potentially leading to shock and death if not treated promptly.
- Ectopic pregnancy (also listed under other likely diagnoses due to its frequency but included here for emphasis on not missing it): Given its potential for severe consequences, including death, if not diagnosed and treated promptly.
- Mesenteric ischemia: A condition where the blood flow to the intestine is blocked, leading to tissue death and potentially life-threatening complications if not addressed quickly.
- Pneumonia (lower lobe): Can cause referred pain to the abdomen, especially if the diaphragm is irritated.
Rare Diagnoses
- Right lower lobe pneumonia: Though more commonly associated with upper abdominal or chest pain, in some cases, it can refer pain to the right lower abdomen.
- Endometriosis: A condition where tissue similar to the lining inside the uterus grows outside of it, causing pain, especially during menstruation.
- Diverticulitis: Inflammation of the diverticula (small pouches) in the wall of the colon, which can cause abdominal pain, usually on the left side but can be on the right in some cases.
- Carcinoid tumor: A rare type of tumor that can cause abdominal pain, flushing, and diarrhea, often associated with the small intestine.