ICD-9 Diagnosis Code 540.9

Acute appendicitis NOS

Diagnosis Code 540.9

ICD-9: 540.9
Short Description: Acute appendicitis NOS
Long Description: Acute appendicitis without mention of peritonitis
This is the 2014 version of the ICD-9-CM diagnosis code 540.9

Code Classification
  • Diseases of the digestive system (520–579)
    • Appendicitis (540-543)
      • 540 Acute appendicitis

Information for Medical Professionals

Information for Patients


The appendix is a small, tube-like organ attached to the first part of the large intestine. It is located in the lower right part of the abdomen. It has no known function. A blockage inside of the appendix causes appendicitis. The blockage leads to increased pressure, problems with blood flow, and inflammation. If the blockage is not treated, the appendix can burst and spread infection into the abdomen. This causes a condition called peritonitis.

The main symptom is pain in the abdomen, often on the right side. It is usually sudden and gets worse over time. Other symptoms may include

  • Swelling in the abdomen
  • Loss of appetite
  • Nausea and vomiting
  • Constipation or diarrhea
  • Inability to pass gas
  • Low fever

Not everyone with appendicitis has all these symptoms.

Appendicitis is a medical emergency. Treatment almost always involves removing the appendix. Anyone can get appendicitis, but it is more common among people 10 to 30 years old.

NIH: National Institute of Diabetes and Digestive and Kidney Diseases

  • Appendectomy
  • Appendicitis - NIH (National Institute of Diabetes and Digestive and Kidney Diseases)
  • Appendicitis

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