Appendicitis is when the appendix becomes swollen, inflamed, and filled with pus. Pain associated with appendicitis may start near the belly button and then move lower and to the right.

The appendix is a small finger-shaped organ on the right side of the abdomen, connected to the large intestine. Its exact purpose is unclear, and a person can live without one.

An X-ray showing an inflamed appendix.Share on Pinterest
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Appendicitis refers to the inflammation of the appendix. It generally occurs when the appendix is blocked, which causes blood flow problems, inflammation, infection, and pressure. Without treatment, the appendix can burst.

Appendicitis can occur at any age, but it most commonly affects people in their teens and 20s.

There are two types of appendicitis:

Acute appendicitis

Acute appendicitis is the more common type of appendicitis. A 2023 article notes that the onset typically occurs over 24 hours.

Appendicitis is a medical emergency and needs to be evaluated quickly. In 2% of cases, the appendix ruptures 36 hours after the onset of initial symptoms. Without treatment, the risk then increases by about 5% for every 12 hours after.

Chronic appendicitis

Chronic appendicitis is a rare form of appendicitis that lasts longer than acute appendicitis. Although the exact cause is unclear, it is thought that chronic appendicitis occurs due to a partial blockage of the appendix.

Chronic appendicitis is a less severe, continuous pain that can last for weeks.

Unlike acute appendicitis, healthcare professionals do not consider chronic appendicitis a medical emergency. A CT scan can help diagnose chronic appendicitis, and treatment involves removing the appendix.

The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) states that the most common symptom of appendicitis is abdominal pain that begins near the belly button. It will then progress lower and to the right.

The pain may:

  • begin suddenly and wake a person when sleeping
  • worsen with movement, coughing, sneezing, or deep breaths
  • be severe
  • worsen within hours

Other symptoms include:

Children may present with atypical symptoms. Anyone who experiences progressively worsening pain in the abdomen should seek medical attention.

Other conditions, such as a urinary tract infection, may have similar symptoms. However, they all require urgent medical attention.

A doctor will examine the person and ask some questions about their symptoms. They will also apply pressure to the lower abdominal area to see whether the pain worsens.

If the doctor detects the typical signs and symptoms of appendicitis, they will diagnose it. If not, they will order further tests.

Tests may include:

  • blood tests to check for infection
  • an MRI, CT, or ultrasound scan to see whether the appendix is inflamed
  • urine tests to identify a kidney or bladder infection

The NIDDK states that a doctor will prescribe antibiotics for anyone with appendicitis.

In some cases, this is enough to treat appendicitis, and surgery will not be necessary. In most cases, however, a surgeon must remove the appendix. This is called an appendectomy.

According to a 2023 review and meta-analysis, although the cure rate is lower than with surgery, treatment with antibiotics may be an option for those with uncomplicated acute appendicitis who do not wish to have surgery.

There are two methods for removing the appendix, which include:

  • Laparoscopy: This is a precise procedure in which there is minimal loss of blood and only a small incision. As a result, recovery time is faster than with open surgery, and there is less scarring. Laparoscopic, keyhole, or minimally invasive surgery (MIS) involves the following steps:
    1. The surgeon inserts a very thin tube, or laparoscope, which has a tiny video camera and light, into the abdomen through a hollow instrument known as a cannula.
    2. The surgeon views the inside of the abdomen, magnified, on a monitor.
    3. Tiny instruments respond to the movements of the surgeon’s hands, and the appendix is removed through small abdominal incisions.
  • Open surgery: In some cases, a larger incision will be made so that the area inside the abdominal cavity can be cleaned. This will happen if:
    • the appendix has ruptured and formed a mass
    • the person has had many abdominal surgeries before

After open surgery, a doctor will give the person antibiotics intravenously.

According to the United Kingdom’s National Health Service (NHS), a person who has had laparoscopic surgery can go home after 24 hours. If open surgery was necessary, they may have to stay in the hospital for up to a week.

For the first few days, a person may experience some constipation, pain, and bruising.

There may also be pain at the tip of the shoulder. During the surgery, the surgeon pumps gas into the abdomen. This can stimulate the phrenic nerve at the diaphragm, causing referred pain. Referred pain occurs at a location other than where the real source of pain exists.

Over-the-counter (OTC) pain relievers may help with postsurgical pain.

After a couple of weeks, a person should be able to resume their usual activities. However, they may need to avoid strenuous activity for 4 to 6 weeks. The doctor will advise about how much activity is suitable at each stage of recovery.

If there are signs of infection, it is important to contact the doctor.

Signs of infection include:

  • worsening pain and swelling
  • repeated vomiting
  • high temperature
  • the site of the operation is hot to touch
  • the site of the operation has pus or other discharge

There is no proven way to prevent appendicitis.

Knowing the signs and symptoms and when to contact a doctor can be helpful.

Appendicitis is the most common non-pregnancy-related emergency requiring surgery during pregnancy.

Diagnosis of appendicitis can be difficult during pregnancy because the common symptoms of appendicitis are not always present. In addition, the symptoms can be similar to those experienced from pregnancy itself.

Symptoms include:

  • pain
  • nausea
  • appetite loss
  • vomiting
  • fever

Atypical symptoms include:

Physical examination may be difficult depending on how far the person has progressed in their pregnancy. Biochemical markers for appendicitis used in laboratory work may be unreliable during pregnancy. Imaging may be used for diagnosis.

As in people who are not pregnant, the cause of appendicitis during pregnancy is usually a blockage that produces inflammation and infection. Surgery to remove the appendix is often the recommended course of treatment.

The following are possible complications of appendicitis:

Peritonitis

If the appendix ruptures and releases the infection into the abdomen, a person may develop peritonitis. Peritonitis is infection and inflammation of the peritoneum, which is the membrane that lines the abdominal cavity and covers most of the abdominal organs.

Peritonitis can cause bowel movements to stop, causing the bowel to become blocked. This can lead to fever and a person could go into shock.

Peritonitis requires urgent treatment.

Abscess

If the infection seeps out of the appendix and mixes with intestinal contents, it can form an abscess, which, without treatment, can cause peritonitis.

Sometimes, antibiotics can treat an abscess. Often, a doctor will surgically drain the abscess with the aid of a tube placed into the abdomen.

Other complications

Other complications include:

  • ileus, which is when the bowel does not work correctly
  • a fistula, which is an abnormal connection between the stomach and the intestine
  • small bowel obstruction
  • infection at the surgical site

The complications of appendicitis can be life threatening. Anyone who may have appendicitis should seek medical help immediately.

Appendicitis is a serious condition that requires immediate treatment.

If any of the symptoms of appendicitis are present, call a doctor or visit an emergency department.

Appendicitis is when the appendix, a small, tube-shaped organ attached to the large intestine, becomes blocked and infected. It is a serious medical condition that requires a quick evaluation.

Appendicitis is generally acute, with symptoms coming on over the course of a day and becoming severe rapidly. Chronic appendicitis can also occur, although it is rare. In chronic cases, symptoms are less severe and can last for days, weeks, or even months.

Treatment for appendicitis will depend on how severe the case is. A person may need to undergo surgery, which can be performed laparoscopically or through an open incision. A person may need to take antibiotics to treat the infection before surgery or in mild cases.