Appendicitis typically starts as a dull ache around the belly button that migrates to the lower right side of the abdomen over 12 to 24 hours. That pain pattern, combined with nausea, loss of appetite, and a low-grade fever, is the classic signal. No home test can confirm or rule out appendicitis on its own, but knowing what doctors look for can help you recognize when lower abdominal pain needs emergency attention.
The Classic Pain Pattern
The hallmark of appendicitis is pain that moves. It often begins as a vague, hard-to-pinpoint discomfort near the navel, then shifts to the lower right abdomen over several hours. Once it settles in that area, the pain typically sharpens and intensifies. Walking, coughing, or even hitting a speed bump in the car can make it worse, because any jostling irritates the inflamed tissue around the appendix.
Other symptoms that commonly accompany the pain include loss of appetite, nausea or vomiting (usually after the pain starts, not before), a low-grade fever around 99 to 100°F, and an inability to pass gas. Not everyone gets every symptom, and the order can vary, but pain that steadily worsens over 6 to 12 hours and concentrates in the lower right abdomen is the most reliable warning sign.
Physical Signs You Can Check at Home
These simple checks mimic what an emergency room doctor would do during a physical exam. They aren’t a substitute for professional evaluation, but they can help you decide how urgently you need to get to a hospital.
- McBurney’s point tenderness: Press gently on a spot about one-third of the way from your right hip bone toward your navel. Sharp, localized pain at that spot is one of the most consistent signs of appendicitis.
- Rebound tenderness: Press down slowly on the lower right abdomen, then release quickly. If the pain spikes when you let go rather than when you push in, that suggests the lining of the abdominal cavity is inflamed.
- Cough test: A sharp increase in right-sided abdominal pain when you cough (called Dunphy’s sign) points toward peritoneal irritation, which happens when the appendix is inflamed.
- Rovsing’s sign: Press on the left lower abdomen. If this triggers pain on the right side, it suggests the right-sided inflammation characteristic of appendicitis.
Two additional tests work best with someone helping you. For the psoas sign, lie on your left side and have someone extend your right leg straight back at the hip. Pain during this motion suggests an inflamed appendix sitting near that deep hip muscle. For the obturator sign, lie on your back with your right knee bent, and have someone rotate your leg inward at the hip. Pain during this rotation suggests the appendix is positioned near the obturator muscle in the pelvis.
What Happens in the Emergency Room
Doctors use a combination of physical exam findings, blood work, and imaging to confirm or rule out appendicitis. No single test is definitive on its own.
Blood tests look for signs of infection and inflammation. A white blood cell count above 12,000 per cubic millimeter raises suspicion. A blood marker called C-reactive protein above 3 mg/dL adds further evidence. When both are elevated together, the likelihood of appendicitis jumps significantly, with roughly eight times the odds compared to someone with normal levels.
Doctors often use a scoring tool called the Alvarado score to estimate the probability. It assigns points for symptoms like pain migration (1 point), nausea (1 point), loss of appetite (1 point), right lower quadrant tenderness (2 points), rebound pain (1 point), fever (1 point), and elevated white blood cell counts (up to 3 points), for a maximum of 10. Higher scores push toward imaging or surgery; lower scores may mean watchful waiting or alternative diagnoses.
CT Scans vs. Ultrasound
A CT scan is the most accurate imaging test for appendicitis in adults. It correctly identifies appendicitis about 97% of the time and correctly rules it out about 96% of the time. Using both oral and intravenous contrast dye pushes accuracy even higher, to roughly 99% sensitivity. Even low-dose CT, which uses less radiation, performs well at about 93% sensitivity.
Ultrasound is less accurate overall, correctly detecting appendicitis about 82% of the time. It’s the preferred first choice for children and pregnant women because it involves no radiation. For pregnant patients, if ultrasound is inconclusive, MRI is the recommended next step. CT is reserved as a last resort during pregnancy when both ultrasound and MRI fail to give a clear answer.
How Appendicitis Differs During Pregnancy
As the uterus grows, it pushes the appendix upward and deeper into the abdomen. This means the pain may not show up in the classic lower right location. During the second and third trimesters, appendicitis pain can appear higher on the right side, sometimes near the ribs, which makes it harder to recognize. If you’re pregnant and have persistent right-sided abdominal pain at any height, that warrants urgent evaluation even if it doesn’t match the textbook description.
Conditions That Mimic Appendicitis
Dozens of conditions can cause similar right-sided abdominal pain. The most common mimics include kidney stones, urinary tract infections, ovarian cysts, gastroenteritis, and gallbladder inflammation. In women of reproductive age, pelvic inflammatory disease and ectopic pregnancy are important to rule out. Doctors distinguish these through a combination of pelvic exam, urine tests, pregnancy tests, and imaging.
A few clues help separate appendicitis from its imitators. With appendicitis, loss of appetite is almost always present, and the pain typically starts before vomiting. In gastroenteritis, vomiting and diarrhea usually come first. Pelvic inflammatory disease tends to cause pain on both sides, vaginal discharge, and pain during a pelvic exam. A positive pregnancy test shifts attention toward ectopic pregnancy.
In children, appendicitis is misdiagnosed 25 to 30% of the time, most often confused with gastroenteritis or respiratory infections. Younger children are harder to diagnose because they can’t always describe or locate their pain precisely. Children who vomit before the onset of pain, have diarrhea, or show signs of a respiratory infection are more likely to be initially misdiagnosed.
What Happens After Diagnosis
Surgery to remove the appendix remains the standard treatment for both uncomplicated and complicated appendicitis. Most appendectomies are now done laparoscopically, through a few small incisions, with a hospital stay of one to two days and a recovery period of two to four weeks. In certain situations, such as when a well-formed abscess has developed or the patient has had symptoms for an extended period, doctors may start with antibiotics and drainage before considering surgery later.
The key factor in outcomes is timing. An inflamed appendix can rupture, typically within 36 to 72 hours of symptom onset, spreading infection into the abdominal cavity. That’s why steadily worsening right-sided pain, especially with fever and nausea, should be treated as an emergency regardless of what any home test suggests.