Diagnosis of Appendicitis

How do doctors diagnose appendicitis?

Most often, health care professionals suspect the diagnosis of appendicitis based on your symptoms, your medical history, and a physical exam. A doctor can confirm the diagnosis with an ultrasound, x-ray, or MRI exam.

Medical history

A health care professional will ask specific questions about your symptoms and health history to help rule out other health problems. The health care professional will want to know

  • when your abdominal pain began
  • the exact location and severity of your pain
  • when your other symptoms appeared
  • your other medical conditions, previous illnesses, and surgical procedures
  • whether you use medicines, alcohol, or illegal drugs

Physical exam

Health care professionals need specific details about the pain in your abdomen to diagnose appendicitis correctly. A health care professional will assess your pain by touching or applying pressure to specific areas of your abdomen.

The following responses to touch or pressure may indicate that you have appendicitis:

  • Rovsing's sign
  • Psoas sign
  • Obturator sign
  • Guarding
  • Rebound tenderness
  • Digital rectal exam
  • Pelvic exam

Lab tests

Doctors use lab tests to help confirm the diagnosis of appendicitis or find other causes of abdominal pain.

Blood tests. A health care professional draws your blood for a blood test at a doctor’s office or a commercial facility. The health care professional sends the blood sample to a lab for testing. Blood tests can show a high white blood cell count, a sign of infection. Blood tests also may show dehydration or fluid and electrolyte imbalances.

Urinalysis. Urinalysis is testing of a urine sample. You will provide a urine sample in a special container in a doctor’s office, a commercial facility, or a hospital. Health care professionals can test the urine in the same location or send it to a lab for testing. Doctors use urinalysis to rule out a urinary tract infection or a kidney stone.

Pregnancy test. For women, health care professionals also may order blood or urine samples to check for pregnancy.

Imaging tests

Doctors use imaging tests to confirm the diagnosis of appendicitis or find other causes of pain in the abdomen.

Abdominal ultrasound. In an ultrasound, a health care professional uses a device, called a transducer, to bounce safe, painless sound waves off of your organs to create an image of their structure. He or she can move the transducer to different angles to examine different organs.

In an abdominal ultrasound, a health care professional applies a gel to your abdomen and moves a hand-held transducer over your skin. A health care professional performs this procedure in a doctor’s office, an outpatient center, or a hospital, and you don’t need anesthesia.

A radiologist reviews the images, which can show signs of

  • a blockage in your appendiceal lumen
  • a burst appendix
  • inflammation
  • other sources of abdominal pain

Health care professionals use an ultrasound as the first imaging test for possible appendicitis in infants, children, young adults, and pregnant women.

Magnetic resonance imaging (MRI). MRI machines use radio waves and magnets to produce detailed pictures of your body’s internal organs and soft tissues without using x-rays.

A health care professional performs the procedure in an outpatient center or a hospital. A radiologist reviews the images. Patients don’t need anesthesia, although a health care professional may give light sedation, taken by mouth, to children and people with a fear of small spaces. A health care professional may inject a special dye, called contrast medium, into your body.

In most cases, you’ll lie on a table that slides into a tunnel-shaped device. The tunnel may be open ended or closed at one end.

An MRI can show signs of

  • a blockage in your appendiceal lumen
  • a burst appendix
  • inflammation
  • other sources of abdominal pain

When diagnosing appendicitis and other sources of abdominal pain, doctors can use an MRI as a safe, reliable alternative to a computerized tomography (CT) scan.2

CT scan. CT scans use x-rays and computer technology to create images.

A health care professional may give you a solution to drink and an injection of contrast medium. You’ll lie on a table that slides into a tunnel-shaped device that takes the x-rays. X-ray technicians perform CT scans in an outpatient center or a hospital. Radiologists review the images.

Patients don’t need anesthesia, although health care professionals may give children a sedative to help them fall asleep for the test.

A CT scan of the abdomen can show signs of inflammation, such as

  • an enlarged or a burst appendix
  • an appendiceal abscess
  • a blockage in your appendiceal lumen

Women of childbearing age should have a pregnancy test before having a CT scan. The radiation from CT scans can be harmful to a developing fetus.

References

November 2014
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This content is provided as a service of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), part of the National Institutes of Health. The NIDDK translates and disseminates research findings through its clearinghouses and education programs to increase knowledge and understanding about health and disease among patients, health professionals, and the public. Content produced by the NIDDK is carefully reviewed by NIDDK scientists and other experts.