Inflammation is just an activation of the immune defense system - the swelling is entirely intentional and healthy. What is annoying the immune defense system is the problem, and can in some cases be caused by a bug in the system (auto-immune disease).

Erroneously attributing correlation as causation is a common mistake. Blood cholesterol - entirely distinct from dietary cholesterol - was also commonly completely misunderstood as a cause, even though it like inflammation is a healthy and necessary response turned into a symptom...