Vasculitis is inflammation of blood vessels that can damage vessel walls and reduce blood flow. It has many causes and can affect vessels of any size throughout the body. Diagnosis involves ruling out other conditions and may include imaging tests and biopsy. Treatment focuses on removing triggers if possible, treating underlying diseases, and using glucocorticoids and other immunosuppressants for primary vasculitic syndromes depending on severity and organ involvement. The goal is to control inflammation and prevent organ damage while minimizing treatment side effects.