Appendicitis, an inflammation of the appendix, is a common cause of sudden abdominal pain. This condition occurs when the appendix, a small, finger-shaped pouch projecting from the large intestine, becomes blocked and infected. While it can affect anyone, it is most frequently observed in individuals between the ages of 5 and 45. Untreated appendicitis can lead to serious complications, such as a ruptured appendix, which can spread infection throughout the abdomen and become life-threatening. Timely and accurate diagnosis is essential for appropriate medical intervention.
Patient History and Physical Examination
The diagnostic process begins with gathering the patient’s medical history and a physical examination. Doctors inquire about the onset, location, and progression of abdominal pain, often the first symptom. A classic presentation involves pain starting around the navel and then shifting to the lower right side of the abdomen. This migratory pain is a distinguishing feature.
Patients often report other symptoms like nausea, vomiting, and a loss of appetite, which usually follow the onset of pain. A low-grade fever may also be present as the body responds to inflammation or infection. During the physical examination, the doctor gently presses on the abdomen to identify areas of tenderness, especially in the lower right quadrant over McBurney’s point, a specific location associated with the appendix.
Further examination involves checking for rebound tenderness, where pain worsens when pressure is quickly released from the abdomen. Specific maneuvers, such as the Rovsing’s sign (pain in the lower right quadrant when the lower left is pressed), the Psoas sign (pain when extending the right hip), and the Obturator sign (pain with internal rotation of the flexed right hip), can also indicate appendiceal inflammation. These findings help indicate appendicitis.
Blood and Urine Analysis
Following the initial assessment, laboratory tests provide additional evidence to support or challenge a diagnosis of appendicitis. A complete blood count (CBC) is performed to measure white blood cells (WBCs). An elevated WBC count often indicates the presence of infection or inflammation within the body.
Another inflammatory marker, C-reactive protein (CRP), is also frequently measured. CRP levels tend to rise within 12 to 24 hours after symptoms begin and can further support inflammation, especially when combined with an elevated WBC count. While these blood tests suggest inflammation, they are not definitive for appendicitis on their own, as other conditions can also cause similar elevations.
A urinalysis is an important part of the diagnostic workup, primarily to rule out other conditions that can mimic appendicitis symptoms. This test checks for signs of a urinary tract infection (UTI) or kidney stones, which can cause abdominal pain similar to appendicitis. While mild urine abnormalities can occur with appendicitis, significant findings usually point to a urinary issue. For women of childbearing age, a pregnancy test is also performed to exclude ectopic pregnancy, which shares similar pain patterns.
Medical Imaging Scans
Medical imaging plays a significant role in definitively diagnosing appendicitis and distinguishing it from other conditions. An abdominal ultrasound is often the initial imaging choice, particularly for children and pregnant women, because it does not involve radiation exposure. On an ultrasound, an inflamed appendix typically appears swollen, with an outer diameter of 6 millimeters or greater.
Computed tomography (CT) scans are the most accurate imaging test for adults suspected of having appendicitis. A CT scan provides detailed cross-sectional images of the abdomen, clearly showing a swollen appendix, inflammation in surrounding tissues, and any fluid collections. CT scans can also identify a normal appendix and rule out other causes of pain, contributing to their effectiveness.
Magnetic resonance imaging (MRI) serves as a valuable alternative, especially when CT scans are contraindicated, such as in pregnant women or when radiation exposure is a concern. MRI offers similar diagnostic accuracy to CT and can effectively visualize an inflamed appendix and surrounding structures without using ionizing radiation. These imaging modalities provide visual confirmation of an inflamed appendix, which guides treatment decisions.
Considering Other Possible Diagnoses
Diagnosing appendicitis can be challenging because its symptoms often overlap with those of many other abdominal conditions. This necessitates a process called differential diagnosis, where doctors consider and rule out other potential causes for a patient’s symptoms. Conditions such as gastroenteritis, which causes stomach upset and pain, can present similarly to early appendicitis.
In females, gynecological issues like ovarian cysts, pelvic inflammatory disease, or ectopic pregnancy can produce pain in the lower abdomen that mimics appendicitis. Kidney stones or urinary tract infections are also common culprits for abdominal pain that might be confused with appendicitis. Diverticulitis, an inflammation of pouches in the digestive tract, can also cause pain in a similar region. The comprehensive approach, combining patient history, physical examination, blood and urine tests, and advanced imaging, allows doctors to systematically exclude these other conditions and arrive at the correct diagnosis.