What Causes Appendicitis: Causes of Appendix Inflammation

Appendicitis is inflammation of a small outpouching of the cecum that requires emergency care in a hospital. We explain what causes it, who is at risk, and how to tell alarming abdominal pain from ordinary pain.

What the appendix and appendicitis are

The appendix is a small tube-shaped organ attached to the beginning of the large intestine in the lower right part of the abdomen. It has no known function, and removing it is not harmful. Appendicitis is swelling and inflammation of the appendix. Without treatment, the appendix can rupture, and the infection can spread through the abdomen — peritonitis develops.

What causes the appendix to become inflamed: main causes

There is one cause: the lumen of the appendix becomes blocked. As a result, mucus accumulates inside, pressure rises, blood flow is impaired, and the wall swells and becomes inflamed. Then the intestinal microflora joins in, and necrosis — tissue death — may begin in the wall.

The main cause of blockage is coproliths, also called fecal stones. They account for almost 100% of cases of purulent, gangrenous, and gangrenous-perforated appendicitis.

• kinking of the appendix by scar adhesions — a consequence of chronic abdominal diseases: colitis, cholecystitis, enteritis, adnexitis, perityphlitis, adhesive disease;
• swallowed foreign bodies — grape seeds, fish and bird bones, sunflower seed husks, small hard objects;
• helminths, more often roundworms — such cases are now rare.

Blockage of the appendix lumen: how it leads to inflammation

Normally, the diameter of the appendix is 4–6 mm. When blocked, it stretches to 17–18 mm or more and becomes tense. Rising pressure over several hours compresses the veins, impairs the outflow of blood and lymph, and swelling of the wall appears. Necrosis is quickly infected by intestinal contents — sometimes it takes less than 12 hours for the wall to break down. When the damage reaches the outer lining, the necrotic plug is pushed out, the appendix perforates, and pus enters the abdominal cavity.

Who gets appendicitis more often

The incidence of acute appendicitis is 4–5 cases per 1000 people per year. Among acute surgical abdominal diseases, it ranks first — 89.1% — and most often leads to peritonitis. It occurs at any age, more often in young and middle age: usually people aged 10–30. Women are affected more often than men.

When abdominal pain requires urgent medical attention

Appendicitis usually begins with pain in the middle of the abdomen, near the navel. After a few hours, it moves to the lower right part and intensifies: it hurts more to move, cough, or press on the abdomen, and if you pull your knees to your chest, it becomes slightly easier. There may be nausea and vomiting, loss of appetite, fever, constipation or diarrhea, and frequent urination. In pregnant women, young children, and older people, the pain may be milder, develop more slowly, or be felt in another location; in older people, sudden confusion sometimes occurs. If the pain suddenly subsides for a short time and then becomes severe and spreads throughout the abdomen, this resembles a ruptured appendix. The diagnosis is not made based on a single symptom: the doctor examines the abdomen, orders blood and urine tests, ultrasound or CT, if necessary a pregnancy test, and sometimes observes the patient in the hospital for several hours.

Call 103 or 112 if abdominal pain is very severe, confusion appears, the skin is pale or mottled (on dark skin this is more noticeable on the palms and soles), or breathing is difficult — such signs may indicate sepsis. If abdominal pain worsens or pain has moved to the lower right, seek medical help urgently.

This material is for reference: it does not replace a doctor's consultation, and if in doubt, it is better to see a surgeon.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer