Appendicitis, Causes, Signs and Symptoms, Diagnosis and Treatment.

Appendicitis is inflammation of the appendix.Symptoms commonly include right lower abdominal pain, nausea, vomiting, and decreased appetite.However, approximately 40% of people do not have these typical symptoms.Severe complications of a ruptured appendix include widespread, painful inflammation of the inner lining of the abdominal wall and sepsis.

Appendicitis is caused by a blockage of the hollow portion of the appendix.This is most commonly due to a calcified "stone" made of feces.Inflamed lymphoid tissue from a viral infection, parasites, gallstone, or tumors may also cause the blockage.This blockage leads to increased pressures in the appendix, decreased blood flow to the tissues of the appendix, and bacterial growth inside the appendix causing inflammation.The combination of inflammation, reduced blood flow to the appendix and distention of the appendix causes tissue injury and tissue death.If this process is left untreated, the appendix may burst, releasing bacteria into the abdominal cavity, leading to increased complications.

The diagnosis of appendicitis is largely based on the person's signs and symptoms.In cases where the diagnosis is unclear, close observation, medical imaging, and laboratory tests can be helpful. The two most common imaging tests used are an ultrasound and computed tomography (CT scan).CT scan has been shown to be more accurate than ultrasound in detecting acute appendicitis.However, ultrasound may be preferred as the first imaging test in children and pregnant women because of the risks associated with radiation exposure from CT scans.