Certolizumab pegol is a medication used to treat autoimmune diseases such as rheumatoid arthritis, Crohn's disease, and psoriatic arthritis. It works by inhibiting a protein called tumor necrosis factor-alpha (TNF-alpha), which plays a key role in inflammation and immune responses. This drug is administered via injection and is designed to reduce symptoms like pain and swelling. By targeting TNF-alpha, certolizumab pegol helps improve the quality of life for patients suffering from chronic inflammatory conditions. Regular monitoring by a healthcare provider is essential during treatment.