Appendicitis
Appendicitis is inflammation of the appendix and is a common surgical emergency. Pain often begins near the middle of the abdomen and moves toward the lower right, but the pattern can vary, especially in children, pregnancy and older adults.
At a glance
Quick facts
- Category
- Acute abdominal emergency
- Typical symptom
- Worsening abdominal pain
- Classic location
- Right lower abdomen
- Diagnosis
- Clinical assessment + labs / imaging
- Main treatment
- Antibiotics + often appendectomy
- Major complication
- Perforation / peritonitis
Dr. Francis Chibueze Nwokpoku
Medical Officer · 9th Division Hospital, Nigerian Army
Reviewed for clinical accuracy, important omissions and patient-facing safety wording.
Names & terminology
How this entity may be named or searched
- Appendicitis
- Inflammation of the vermiform appendix.
- Acute appendicitis
- The usual sudden-onset clinical form.
- Perforated / ruptured appendix
- Appendicitis complicated by a hole in the appendix wall and contamination of the abdomen.
- Appendiceal abscess
- A localized collection of infection that can form after perforation.
Structured entity profile
Clinical profile
Overview
Appendicitis is inflammation of the appendix, a small pouch attached to the large intestine. NIDDK describes it as the most common cause of acute abdominal pain requiring surgery in the United States. [1]
About 5 to 9 in every 100 people develop appendicitis at some point in life. It can occur at any age but is especially common in the teens and 20s. [1]
Symptoms and warning signs
The most typical pattern is abdominal pain that starts near the navel and moves down and to the right, becoming worse over hours. Loss of appetite, nausea, vomiting, fever, abdominal swelling, constipation or diarrhea can occur. Not everyone has the classic pattern. [2]
SYMPTOM MATRIX
Appendicitis pain often evolves over hours
Because rupture can occur, worsening unexplained abdominal pain needs prompt medical assessment.
- Abdominal pain
- Pain moving toward lower right abdomen
- Pain worse with movement, cough or deep breath
- Loss of appetite
- Nausea or vomiting
- Fever
- Abdominal swelling
- Constipation or diarrhea
- Difficulty passing gas
- Atypical pain location
- Severe or rapidly worsening abdominal pain
- Rigid or very tender abdomen
- High fever or marked illness
- Fainting, confusion or dehydration
Suspected appendicitis should be assessed urgently; symptoms alone cannot reliably determine whether the appendix has perforated.
Diagnosis
Clinicians combine the history, abdominal examination and laboratory tests. Blood tests can look for infection or inflammation; urine testing and pregnancy testing may help identify other causes of pain. [3]
Ultrasound, CT or MRI can support the diagnosis and identify alternatives or complications. Imaging selection varies by age, pregnancy and local practice. [3]
Diagnostic pathway
Appendicitis is a clinical diagnosis supported by tests
The goal is to confirm appendicitis while also considering other causes of acute abdominal pain.
No single normal laboratory result reliably excludes appendicitis when the overall clinical picture remains concerning. Source [3]
Perforation, abscess and peritonitis
Untreated appendicitis can perforate. Infection may then spread through the abdomen as peritonitis or become walled off as an appendiceal abscess. These complications usually require hospital treatment and can change the timing or type of surgery. [1] [4]
Treatment and management
Doctors commonly treat appendicitis with antibiotics and appendectomy. Appendectomy can be laparoscopic or open; prompt surgery reduces the chance of rupture and related complications. [4]
When uncomplicated appendicitis is treated without surgery, patients should understand that recurrence can occur and later appendectomy may still become necessary.
Selected uncomplicated cases may be managed with antibiotics without immediate surgery, but recurrence or later appendectomy can occur. Perforation, abscess or peritonitis requires individualized surgical and infection management. [4]
Treatment & care hub
Treat early and tailor care to complications
Uncomplicated disease and perforated appendicitis follow different pathways.
Treat bacterial infection risk
Antibiotics are commonly part of appendicitis treatment and perioperative care.
Remove the inflamed appendix
Laparoscopic or open surgery is chosen according to anatomy, complications and surgical context.
Antibiotics alone in some uncomplicated cases
Careful selection and follow-up are needed because appendicitis can recur.
Manage perforation or abscess
Drainage, broader infection treatment and adjusted surgery timing may be required.
Recovery after appendicitis
Most people recover well after uncomplicated appendectomy. Recovery is longer after perforation or abscess. Worsening pain, persistent fever, vomiting, wound redness or inability to eat or drink should prompt reassessment. [4]
Lifetime risk estimate
Appendicitis affects roughly 5–9% of people in the United States
NIDDK summarizes appendicitis as a common cause of emergency abdominal surgery.
Common questions
Frequently asked questions
It often begins near the belly button and later moves toward the lower right abdomen, but this classic pattern is not present in everyone.
Some selected uncomplicated cases can be treated with antibiotics, but recurrence can occur and many patients still need appendectomy.
Diagnosis combines examination, blood and urine testing, and imaging such as ultrasound, CT or MRI when appropriate.
Yes. Untreated appendicitis can perforate and cause an abscess or peritonitis.
Yes. Progressive abdominal pain with features concerning for appendicitis warrants prompt medical assessment.
Sources
- NIDDK, NIH — Definition & Facts for Appendicitis
- NIDDK, NIH — Symptoms & Causes of Appendicitis
- NIDDK, NIH — Diagnosis of Appendicitis
- NIDDK, NIH — Treatment for Appendicitis
This article is based on trusted medical sources and has undergone clinician review. It is not a substitute for personalized medical advice.
A normal ultrasound does not by itself rule out appendicitis. History, examination and the overall clinical probability remain important when deciding whether further imaging or observation is needed.
Clinical examination remains a central part of assessing suspected acute appendicitis, rather than relying on imaging alone.