Appendicitis

Medically Reviewed by Jabeen Begum, MD on March 20, 2024
9 min read

Appendicitis is an inflammation of the appendix. It's a medical emergency that almost always requires surgery as soon as possible to remove the appendix. Luckily, you can live just fine without it.

There are two types of appendicitis:

Acute appendicitis. This is the most common type of appendicitis. Its symptoms start suddenly and get worse quickly within a few hours.

Chronic appendicitis. Chronic appendicitis means that the appendix is inflamed, but it doesn’t typically get any worse. While the symptoms are usually milder, the pain can return over weeks, months, or even years. Because doctors know less about chronic appendicitis, it’s harder to diagnose.

The appendix is a 3 1/2-inch-long tube of tissue that extends from your large intestine on the lower right side of your body. The appendix has specialized tissue that can make antibodies, but no one is completely sure what its function is.

In the U.S., 1 in 20 people will get appendicitis at some point in their lives. Although it can strike at any age, appendicitis is rare in children younger than 2. It’s most likely to affect people between the ages of 10 and 30 and people who were assigned male at birth. If appendicitis runs in your family, you might also be more likely to get it at some point. It’s not a condition that’s passed down, but some genetic factors could put you at a higher risk.

Appendicitis happens when the appendix gets blocked, often by poop, a foreign body (something inside you that isn’t supposed to be there), or cancer. Blockage may also result from infection since the appendix can swell in response to any infection in the body.

Certain conditions can also cause appendicitis, including: 

  • Appendix stones. Old poop can dry up and turn into hard stones that then get stuck in the opening of your appendix. Since these stones carry bacteria and can also trap other bacteria inside your appendix, they’re likely to cause inflammation. 
  • Lymphoid hyperplasia. Your lymphatic system is the part of your immune system that helps your body regulate fluids, filter out bacteria, and create white blood cells. In the case of lymphoid hyperplasia, your lymph nodes start to produce extra cells in response to a virus or infection. Since your appendix has lymphatic tissue, it might react by swelling — even if it’s not the source of the infection. That swelling can cause an obstruction that leads to an infection.
  • Colitis. If your large intestine is inflamed, it could affect your appendix — either through the spread of an infection or because of irritation.
  • Tumors. While rare, tumors can grow inside of your appendix, leading to appendicitis.
  • Parasites. If a parasite blocks or partially blocks the opening of the appendix, it can become inflamed.
  • Cystic fibrosis. Some people with cystic fibrosis have a larger appendix, which may increase their risk of appendicitis.

The classic symptoms of appendicitis include:

  • Pain in your lower right belly or pain near your navel that moves lower. This is usually the first sign. The appendix pain location might be different for some people, depending on where your appendix is. If it’s behind your colon, for example, you may feel pain near your pelvis. If you’re pregnant, the pain might start higher up, as the appendix can move during pregnancy.
  • Loss of appetite
  • Nausea and vomiting soon after belly pain begins
  • Swollen belly
  • Fever of 99-102 F
  • Inability to pass gas

Other less common symptoms of appendicitis include:

  • Dull or sharp pain anywhere in your upper or lower belly, back, or rear end
  • Painful or difficult peeing
  • Vomiting before your belly pain starts
  • Severe cramps
  • Constipation or diarrhea with gas

Atypical signs of appendicitis during pregnancy include:

  • Acid reflux and/or indigestion
  • Pelvic pain
  • Pain beneath your rib cage
  • Pain when urinating

If you have any of these symptoms, see a doctor right away. Acute appendicitis comes on suddenly and develops quickly over 24 hours. Timely diagnosis and treatment are important. Don’t eat, drink, or use any pain remedies, antacids, laxatives, or heating pads.

Diagnosing appendicitis can be tricky. Symptoms are often unclear or similar to those of other illnesses, including gallbladder problems, bladder or urinary tract infection, Crohn's disease, gastritis, kidney stones, intestinal infection, and ovary problems.

These tests can help diagnose appendicitis:

  • Examination of your abdomen to look for inflammation
  • Urine (pee) test to rule out a urinary tract infection
  • Rectal exam
  • Blood test to see whether your body is fighting an infection
  • CT scans (the most accurate method of diagnosis)
  • Ultrasound
  • A pregnancy test and an ultrasound to rule out an ectopic pregnancy (which is a pregnancy that can't continue normally because a fertilized egg has grown outside of your uterus)
  • Pelvic exam to rule out pelvic inflammatory disease, an ovarian cyst, or another condition that affects the reproductive organs

Appendicitis is almost always treated as an emergency. Surgery to remove the appendix, which is called an appendectomy, is the standard treatment for almost all cases of appendicitis.

Generally, if your doctor suspects that you have appendicitis, they will quickly remove it to avoid a rupture. If you have an abscess, you may get two procedures: one to drain the abscess of pus and fluid, and a later one to take out the appendix. But some research shows that treating acute appendicitis with antibiotics may help you avoid surgery.

Before your appendix is taken out, you’ll take antibiotics to fight infection. You’ll usually get general anesthesia, meaning you’ll be asleep for the procedure. You won’t be able to eat or drink for 8 hours before the surgery, but you’ll get fluids through an IV line.

There are two types of appendectomies:

Laparoscopy

This is the most common type of appendectomy because of its quick recovery time. During surgery, a doctor will use a tube to inflate your abdomen with gas so that they can see your appendix better. They will remove your appendix through a 4-inch-long cut or with a device called a laparoscope (a thin telescope-like tool that lets them see inside your belly). If you have peritonitis, the surgeon will also clean out your belly and drain the pus. The surgeon will close the cut with either dissolvable or regular stitches. If you get regular stitches, you’ll need to visit your doctor 7-10 days after surgery to have them removed. You should be able to leave the hospital within 24 hours if there aren’t any complications.

Open surgery 

If your appendix has already burst, or if you’ve had open abdominal surgery in the past, your doctor will make a larger cut in the lower right side of your belly. Once the abdominal area is open, the surgeon will tie off your appendix with stitches and remove it. If your appendix has burst, your abdomen will be washed out with salt water. The cut will be closed with stitches and a small tube may be inserted to drain any extra fluids. If you have peritonitis, your doctor may have to make a cut along the middle of your abdomen. It could take up to 1 week before you’re able to leave the hospital.

After surgery, you may be given pain relievers through an IV. You can drink liquids within a few hours and slowly start to eat more solid foods. After 12 hours, you should be able to get up and move around. It’s normal to have some pain and bruising around the cut. If you had a laparoscopy, you might also have pain in your shoulder or feel bloated from the gas that was pumped into your belly. You can take over-the-counter painkillers to help. It’s important to keep the cut clean and dry while it heals. 

To help with your recovery, limit your activity for 3-5 days after a laparoscopy and 10-14 days after open surgery. If you need to cough, you can support your abdomen by placing a pillow over it and applying pressure. Slowly increase your activity as you feel up for it, starting with short walks, but also rest when you need to. You should be able to go back to your normal routine in 2-3 weeks, but if you had open surgery, avoid strenuous activities for 4-6 weeks.

After an appendectomy, call your doctor if you have:

  • Uncontrolled vomiting
  • Increased belly pain
  • Dizziness/feelings of faintness
  • Blood in your vomit or pee
  • Increased pain and redness where your doctor cut into your belly
  • Fever
  • Pus in the wound

If left untreated, an inflamed appendix will burst, spilling bacteria and debris into the abdominal cavity, the central part of your body that holds your liver, stomach, and intestines. This can lead to peritonitis, a serious infection of the abdominal cavity's lining (the peritoneum). It can be deadly unless it is treated quickly with strong antibiotics and surgery to remove the pus.

Abscess. Sometimes an abscess, or a collection of pus, can develop when your appendix bursts. Usually a doctor will drain the abscess and you'll have your appendix removed during surgery.

Ileus. In some cases, the inflammation of the appendix can trigger ileus, which is when your intestines stop contracting and food can’t move through your digestive system. It’s temporary but might make you feel constipated, bloated, and gassy.

Fistula. While rare, it’s also possible for a fistula to form after an appendectomy. A fistula is a passage between two body parts that shouldn’t be there. In the case of appendicitis, a fistula can form involving the intestines. Fistulas require surgery to fix.

Other complications that can happen after appendicitis include small bowel obstruction (a blockage of food and liquid from your small intestine), an infection at the surgical site, or a miscarriage if you’re pregnant.

There’s no way to prevent appendicitis. But it may be less common in people who eat foods high in fiber, such as fresh fruits and vegetables.

Appendicitis is a medical emergency that requires surgery to remove. Fortunately, living without the appendix doesn’t create any health problems. Prompt diagnosis and treatment are crucial to avoid complications. If you think you have appendicitis, you should see a doctor immediately.

What triggers appendicitis? Viruses, bacteria, or parasites in your digestive tract can cause appendicitis. Poop that blocks the opening of your appendix can also trigger it.

Can appendicitis resolve on its own? In rare cases, appendicitis can go away on its own. But you should always see a doctor if you think you have appendicitis — even if your pain levels start to improve.

How fast does appendicitis progress? Symptoms of appendicitis usually show up within the first 24 hours and progress quickly. If left untreated, the appendix can burst within 48-72 hours.

How to check for appendicitis at home? If your abdominal pain gets worse when you lie on your left side and extend your right hip, or when you flex and rotate your right hip, you may have appendicitis.

Which foods can cause appendicitis? Undigested seeds or nuts have triggered rare cases of appendicitis. A high-fiber diet may reduce your chances of having appendicitis.