What is the primary cause of appendicitis?

The primary cause of appendicitis is inflammation due to obstruction. The appendix can become obstructed by various factors such as stool, foreign bodies, or tumors, which leads to increased pressure, decreased blood flow, and ultimately inflammation and infection. When the appendix is obstructed, bacteria can proliferate within it, causing it to become swollen and tender. This inflammatory response is what characterizes appendicitis and can lead to complications like perforation if not treated promptly.

While tumors in the appendix can occur, they are a much rarer cause of appendicitis compared to obstruction. Genetic predisposition and infections from viruses may play a role in predisposing individuals to various types of conditions, but they are not the primary mechanisms behind appendicitis. It is the obstruction that is the most direct and common cause of the inflammation leading to the condition.