This book explores the complex interplay between oxidative stress, arachidonic acid and inflammatory cytokines in various chronic inflammatory diseases. It describes how the production of ROS (reactive oxygen species) and the release of arachidonic acid, activated by complex biochemical processes, trigger an inflammatory cascade, amplified by the production of mediators such as prostaglandins and leukotrienes. The roles of essential metals such as iron, copper and zinc are also discussed, highlighting their involvement in the control of oxidative stress and inflammatory responses. Through examples of diseases such as rheumatoid arthritis, asthma and cardiovascular disease, the book proposes therapeutic approaches, including antioxidants and IL-6 inhibitors, to reduce inflammation. Finally, it presents perspectives for future research and innovative therapeutic strategies in the treatment of chronic inflammatory diseases.