Causes, Symptoms, Diagnosis And Treatment Options

Appendicitis is the inflammation of the appendix, a 7 to 15 cm long tube-like organ, more like the shape and size of your little finger. It could be longer. It is attached to the beginning large bowel called the cecum. It causes pain on the right lower abdomen, with loss of appetite, nausea and pain when that spot is pressed on. See the causes, how it is diagnosed, as well as treatment options for this condition. You will also be able to share your appendix story here.

The Appendix is a tube-like organ at the beginning of the large intestine. It measures about 7 to 15 cm long and 0.5 to 1.5cm wide. It is the tiniest part of the bowel; a worm-like out pouching at the junction where the small and large intestine meets, near the cecum.  Its definite function is not fully known.

It was once wrongly thought to be a vestigial organ in humans, a remnant of "evolution". It is rare to find an appendix in other animals - only a very few species have it.

Current evidence suggests that the appendix is indeed a very important organ that helps in the immune functions of the bowel. It is believed to house "good bacteria" and releases these good bacteria into the bowel to aid the normal balance and function of gut from time to time.

The appendix is usually located on the right side of lower abdomen. In a few people with what is called situs invertus - a condition where all their organs are switched around to the opposite side of what is normal, the appendix can be located on the left side of their abdomen, and their heart on the right side, instead of the left. So if you are wondering where your appendix could be located, feel for your heart under your left breast, and if you can feel it, it then means that your appendix would be on the right lower abdomen - diagonally opposite your heart.

What Is Appendicitis

Quick Guide: How To Tell If You Are Having Appendicitis

Are you experiencing:

  • Lower right abdominal pain that is made worse by coughing or moving?
  • Feelings of being unwell with or without fever?
  • Loss of appetite?
  • Nausea?
  • Pressing on your lower right abdomen about a hand's breadth to the right and below the umbilicus results in severe pain?

If these symptoms are worsening or persists for more than a day, it is best to seek medical advice as soon as possible.

Appendicitis is the infection or inflammation (severe irritation) of the appendix. It is also called epityphilitis.

It is the most common cause of right lower abdominal pain of a few days duration, associated with loss of appetite, nausea, with or without constipation or diarrhea.

It is also the most common cause for emergency surgical admissions worldwide. About 70,000 operations are done in the UK yearly to remove a diseased appendix. In the US, it is reported that 1 in every ten persons would come down with an inflamed appendix. The incidence of this disease is falling in the industrialized world, but sharply rising in developing countries.

This condition is rare in infants, though it can occur at any age. It is one and a half times more common in men than in women. Women on the other hand are more likely to have unnecessary operation for a presumed appendicitis because of difficulties in differentiating this condition from other common causes of right lower abdominal pain in women. 

Appendicitis in pregnancy is also a common phenomenon, though it tends to be less seen after the seventh month of pregnancy. It is very important to be able to diagnose this condition in a pregnant woman to avoid preventable complications. It is reported that as much as 10 percent (10 out of every 100) pregnant women who have appendicitis in pregnancy end up dying from this; 30 percent of cases of appendicitis in pregnancy end up with a miscarriage and fetal loss; while up to 60 % of appendicitis in pregnancy become perforated(1).


picture of where appendicitis hurts

The symptoms of appendicitis are generally easy to spot in most people. It is a condition that commonly affects those between the ages of 10 and 30 years, though it can occur at any age.

The story is usually that of a vague or cramping central abdominal pain, around the umbilicus or navel. This pain is often ignored or thought to be due to indigestion or "tummy bug". Yes, the early stages of the pain of appendicitis can feel like heartburn.

Within a few hours or 2 to 3 days after the onset of the initial pain or discomfort, patients often report that their pain then move from around the belly button or umbilicus down to the right lower abdomen. 

It is often at this point that most people give attention to the pain because it then becomes a more severe pain. There would be associated:

  • Nausea or feeling like vomiting
  • Loss of appetite - you might notice that you do not fancy eating any thing or have a reduced appetite
  • You might vomit once or twice. Abdominal pain, nausea and loss of appetite is more of features of appendicitis and vomiting, if it ever occurs, comes on later and usually not more than a few times after onset of pain.
  • Tiredness, or feeling hot and cold (fever)
  • Your tongue might become dry and coated, with a peculiar odour doctors call fetor oris
  • There may be a few episodes of diarrhoea especially in children or constipation, more in adults
  • As the infection progresses, the pain becomes worse and you may find out that lying on the right side hurts, or coughing or travelling in a car hurts. You may at this point find out that you are doubling over to keep your abdomen still and all you may want to do is lie still in bed.
  • For some, they may also start passing urine more frequently than usual, should the inflamed appendix be rubbing on their urinary bladder. 

The above symptoms are the typical symptoms of appendicitis. The full picture described above is only seen in about 50% of patients with this condition.

  • Acute appendicitis is a condition difficult to diagnose in babies under two years of age. At this age, the predominant sign and symptoms of appendicitis are those of unexplained crying, fever, diarrhoea and vomiting. A very high index of suspicion coupled with a careful physical examination is the best way finding out if your baby may be suffering with an inflamed appendix.
  • In pregnancy, the diagnosis of an inflamed appendix may also be difficult due to the rising uterus pushing the appendix up, and altering the traditional position of the pain of an inflamed appendix.

Appendicitis does not last for days and weeks generally. It either continues to go bad with worsening symptoms until medical help is sought or gets better within a few days to a week or so.

If you suspect that you might be suffering with acute appendicitis, it is best you seek medical help as soon as possible.


The exact cause of appendicitis is not known.

The appendix, like the other parts of our intestine, has a lumen. On the wall of the lumen, there are some lymph nodes. The cells on the wall of the appendix also secret mucus to keep the appendix lubricated inside.

Appendicitis occurs when the lumen of the appendix becomes blocked for whatever reason and bugs (bacteria) then multiply inside the debris formed due to the blockade and infect the wall of the appendix.

Any blockage leads to a reduction in the blood supply to the part of the appendix below the level of the obstruction. Once the blood supply of any part of the body is reduced, bacteria tend to grow fast there, and colonize the dying tissue. This is understandable because the blood provides nutrients as well as regular supply of white blood cells which act to curtail infection.

So, what are the things that could cause blockage of the lumen of the appendix and cause appendicitis? They include:

  • Small lump of hard faeces ( called faecoliths)
  • Parasitic worms like thread worms in children
  • Benign tumour of the appendix
  • Enlarged lymph nodes around or inside the appendix.

Other causes of appendicitis that has been reported include:

  • Poor dietary fiber
  • Virus infection causing swelling of lymph nodes inside the appendix
  • Spread of infection to the appendix from a gut infection

Is appendicitis contagious? No Appendicitis is not spread by touching someone or coming in contact with an infection of any type.


There is no test or laboratory investigation or imaging technique that can be used to confirm the presence of an inflammation of the appendix with certainty at all times. Diagnosis of appendicitis is mainly based on a good history or story from the patient, a thorough physical examination of the patient and use of supportive blood test and scans, if deemed necessary.

  • Blood tests for inflammation of the appendix include the Full Blood Count, also called Complete Blood Count.
  • The White Blood Cells (WBC) count and the neutrophils count (a type of white blood cell) are the most important parameters to look out for. It is said that the presence of more than 10,000 WBC and not more than 20,000 white blood cells in a milliliter of blood, makes appendicitis very likely, if occurring in association with the symptoms of this disease.
  • While an Abdominal Ultrasound scan and a CT -Scan can help to further give weight to a suspected case, laparoscopy or endoscopy provides the most convincing evidence of the presence of an inflamed appendix.

The Alvarado Score scoring system for appendicitis is a very reliable way of predicting the presence of appendicitis. It adds up a number of common signs and symptoms of this condition, as well as laboratory findings to award a score of 0 to 10.

You can add up the presence or absence the symptoms and findings, and reach an Alvarado score as follows:

  • Presence of pain in the right lower abdomen (scores 2)
  • Pain moved from the upper abdomen to the lower right abdomen (scores 1)
  • Presence of loss of appetite (scores 1)
  • Feeling sick or vomiting (scores 1)
  • Worsening of pain when thr right lower abdomen is pressed and released - rebound tenderness) - scores 1
  • Presence of a temperature more than 37.3 degrees centigrade (scores 1)
  • Presence of raised white blood cells (WBC) in blood test more than 10,000 scores 2
  • Neutrophils shift to the left on blood test (scores 1).

If you have a score of 1 to 4, appendicitis is unlikely, a score of 5-6 makes the presence of an inflamed appendix likely, a score of 7 to 8 means the diagnosis of this condition is most likely and a score of 9 to 10 makes this diagnosis almost certain.

Conditions That Can Cause Symptoms Similar To Appendicitis

The following are conditions that could cause symptoms similar to appendicitis and must be excluded to prevent unnecessary operation for a presumed inflammation of the appendix. They include:


The treatment of appendicitis is by means of surgery. This could be by the use of laparoscopy, also called keyhole surgery. This form of surgery is rapidly replacing open surgery for appendicitis. It is fast, save and has less complications.

Though often less favoured, with a risk of more complications, medical treatment of appendicitis can be undertaken in very special cases. This involves the use of antibiotic combination like a metronidazole and augmentin or cefuroxime intravenously for a few days. 

Medical treatment of appendicitis can be adopted if:

  • There is no access to surgical treatment - eg, if you are away in an isolated part of the world without access to surgery like in a submarine or in Antarctica
  • Patient is too frail to undergo surgery or laparoscopy. 

The operation done to treat the inflammation of the appendix is called appendicectomy or appendectomy (in the US).

You can read more about the treatment of appendicitis here.

ICD 9 and ICD 10 Codes For Acute Appendicitis

For insurance and billing purposes, the ICD 9 code for appendicitis, depending on the details of what you hope to be coding for are:

  • Acute appendicitis ICD 9 Code is 540
  • Appendicitis ICD 9 code if unqualified (not stated if perforated, acute or in pregnancy) is 541
  • Other diseases involving the appendix can be grouped under the ICD 9 code of 543.


Published on the 1st of June 2005 by Editorial Team under causes of lower right sided abdominal pain.
Article was last reviewed on 12th October 2015.

Appendicitis Stories - Have Your Say!

Are you suffering with a right sided abdominal pain? Do you suspect that this might be due to appendicitis? Or have you had your appendix removed? What was your experience like? Share your appendicitis stories here. We would really love to hear from you!

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