The standard treatment for appendicitis is no longer an operation in every case. For a defined group of adults with uncomplicated appendicitis, antibiotics are now supported by randomized trial evidence as an alternative to appendectomy. The signs that should trigger an emergency department visit, however, have stayed the same.
Appendicitis is inflammation of the appendix, a small blind-ended pouch attached to the lower right side of the colon. When the opening becomes blocked, bacteria multiply and the tissue swells. Without treatment, the appendix can burst and release bacteria into the abdominal cavity.
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The condition can occur at any age, but the risk is heavily concentrated in adolescence and early adulthood. Incidence rises after early childhood, peaks between ages 10 and 30, and declines gradually from middle age onward in high-income countries. Across a lifetime, roughly 7 to 8 percent of people will develop appendicitis.
Males are slightly more likely to develop appendicitis during adolescence and early adulthood, though the difference is small. Pregnancy, older age, and being too young to describe pain precisely are the situations most likely to blur the textbook symptoms, which is why diagnosis in those groups can be delayed.
The pain pattern that raises suspicion
The first warning sign is not always pain in the lower right side. In a typical presentation, the discomfort starts as a vague ache near the belly button. Within several hours to about a day, it migrates to the right lower quadrant and becomes sharper, often settling at McBurney's point, a spot about two-thirds of the way from the navel to the front of the right hip bone.
That shift happens because the inflamed appendix first triggers dull, poorly localised visceral pain. Once nearby tissue and the abdominal wall become irritated, the pain is easier to pinpoint. Coughing or walking often makes it worse; some patients notice the same jolt from a car ride.
Other symptoms that accompany appendicitis
Loss of appetite is common, and nausea frequently follows. Vomiting, when it occurs, tends to start after the pain rather than before it. A low-grade fever is typical, while a higher fever can suggest the appendix has already ruptured.
- Pain that starts near the navel and shifts to the lower right abdomen
- Pain that worsens with movement or coughing; a deep breath can also make it sharper
- Nausea or loss of appetite; vomiting may occur later
- Fever or chills
- Constipation or diarrhoea can occur, but these changes are less specific; some people have difficulty passing gas
Children may refuse food, avoid moving, or have pain localised anywhere in the lower abdomen. Pregnant people may feel pain higher on the right side because the growing uterus shifts the appendix upward. Older adults frequently report less pain and a lower fever, which can make the diagnosis look less urgent than it is.
How doctors diagnose appendicitis
No single blood test can confirm appendicitis. A raised white blood cell count and an elevated C-reactive protein level support the diagnosis but are not definitive. The diagnosis rests on a clinical examination plus imaging, with blood tests used as supporting information.
Scoring systems such as the Alvarado score combine symptoms, exam findings, and white cell count to estimate risk. They help emergency clinicians decide who needs urgent imaging and who can be observed. A low score does not rule out appendicitis, but it can reduce unnecessary CT scans in younger patients.
The National Institute of Diabetes and Digestive and Kidney Diseases describes the standard workup similarly: a physical exam, blood and urine tests, and imaging chosen on clinical grounds are used together because no single finding is reliable on its own.
Ultrasound is often the first imaging test for children and pregnant women because it avoids radiation. Its weakness is that it can miss an inflamed appendix, especially in larger adults. CT is the most accurate test in most adults, but it exposes the patient to ionising radiation. When ultrasound is inconclusive in pregnancy, MRI is the next step.
For treatment and research, imaging separates uncomplicated appendicitis from complicated appendicitis, which includes perforation, abscess, or an inflammatory mass. The distinction matters because antibiotics alone are not recommended for complicated appendicitis.
Surgery: still the default for most patients
Laparoscopic appendectomy is the standard operation in many countries. The surgeon removes the appendix through small incisions, usually under general anaesthesia. Open surgery is reserved for cases where the appendix has ruptured, there is severe infection, or laparoscopic equipment is not available.
Most people with uncomplicated appendicitis can go home within one to three days after laparoscopic surgery. Recovery to normal activity often takes one to three weeks, less with laparoscopic than open surgery. The removed appendix is sent to pathology, which sometimes finds a tumour instead of simple inflammation.
Antibiotics for uncomplicated appendicitis: what the trials found
The strongest evidence comes from the CODA trial, which randomly assigned 1,552 U.S. adults with appendicitis to either antibiotics or appendectomy. At 30 days, health-related quality of life was similar between the groups. By 90 days, 29 percent of people assigned to antibiotics had still needed an appendectomy.
Those results changed how doctors frame the choice. Antibiotics are not a cure with a tiny failure rate; they are an initial treatment that lets a substantial majority avoid surgery in the first few years. In the Finnish APPAC trial, 39 percent of patients who initially received antibiotics had a recurrent appendicitis by five years, meaning 61 percent remained free of surgery.
Antibiotics are an option only for adults with uncomplicated appendicitis confirmed on imaging, no appendicolith that would reduce the chance of success, and no signs of perforation or abscess. The CODA trial, published in the New England Journal of Medicine, found that patients with an appendicolith had higher rates of appendectomy and complications. The APPAC five-year follow-up in JAMA documented the long-term recurrence risk.
Complications and when delay becomes dangerous
A burst appendix can cause peritonitis, and an abscess may form around the appendix. Perforation becomes more likely after 48 to 72 hours of untreated symptoms, though not every case follows that timeline. Even with perforation, prompt antibiotics and surgery usually prevent death, but recovery is longer and the risk of complications is higher.
In high-income countries, death from appendicitis is uncommon, and hospital-based reports typically put mortality under 1 percent. Older age and delayed presentation raise the risk of a poor outcome.
Recovery and realistic expectations
After uncomplicated laparoscopic surgery, many patients are discharged the following day. Incision pain usually responds to simple analgesia. Most people can return to desk work within one to two weeks; heavy lifting may need to wait longer. A perforated appendix usually means a longer hospital stay and a course of intravenous antibiotics.
After antibiotic-only treatment, symptoms generally improve within 48 hours, but patients need clear instructions to return if pain worsens or fever develops. Because recurrence is possible, the plan is not watch-and-wait without a defined follow-up.
What to do if you suspect appendicitis
New abdominal pain that starts near the navel and shifts to the right lower side, or pain with vomiting and fever, should be assessed the same day. Do not take laxatives or eat a large meal if appendicitis is possible; both can make a bad situation worse.
Telemedicine is not enough for suspected appendicitis. The diagnosis requires an abdominal examination and, in most cases, imaging. Go to a facility with emergency imaging and surgical services, and do not decide to delay simply because the pain is still tolerable.
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