Which condition is defined as an inflammation of the appendix, usually due to infection?

The condition characterized by inflammation of the appendix, most commonly due to infection, is appendicitis. This occurs when the appendix becomes blocked, often by stool, a foreign body, or cancer, leading to increased pressure and bacterial growth inside the appendix. The inflammation can cause severe abdominal pain, typically starting around the navel and then moving to the right lower quadrant, along with symptoms such as fever and nausea.

Understanding appendicitis is crucial because it often requires timely surgical intervention to remove the inflamed appendix and prevent complications, such as rupture, which can lead to peritonitis, a serious infection of the abdominal cavity. The medical terminology directly reflects the affected organ and type of injury—in this case, "appendicitis" clearly indicates inflammation (itis) of the appendix.

In contrast, cholecystitis refers to inflammation of the gallbladder, pneumonitis is an inflammation of the lung tissue usually due to infection or irritants, and gastritis is the inflammation of the stomach lining. Each of these conditions affects different organs and has distinct causes and treatments.