Vasculitis refers to diseases that cause blood vessel walls to thicken and narrow, cutting off blood supply to tissues and organs. Vasculitis encapsulates several conditions, and the cause of vasculitis is often unknown. This book explores various forms of vasculitis and options for treatment. Chapter One includes a detailed description of giant cell arteritis, a form of vasculitis involving inflammation of the middle and large arteries, including the latest management strategies. Chapter Two concerns different types of vasculitis affecting the lungs, their signs and symptoms, treatment, and complications needed for diagnosis. Chapter Three deals with eosinophilic granulomatosis with polyangiitis, a multisystemic necrotizing vasculitis characterized by allergic rhinitis, asthma, and peripheral eosinophilia. Chapter Four describes the common pathophysiology and cardiovascular complications arising in different vasculidities. Chapter Five reviews the pathophysiology, epidemiology, diagnostic investigation, and treatment of infection etiologies of Herpesviridae associated with vasculitis. Chapter Six elucidates the impact of vasculitis on the gastrointestinal system. Chapter Seven explains hypocomplementic urticarial vasculitis syndrome, defined as presence of greater than six months of urticaria along with hypocomplementemia and multi-system manifestations such as recurrent abdominal pain, uveitis, arthralgia and glomerulonephritis. Chapter Eight explicates the use of biologics in treating rheumatology disorders, with rituximab being recommended in organ-threatening, refractory systemic lupus erythematosus. Lastly, Chapter Nine discusses the pathophysiology and adverse effects of adenoviral vector vaccinations for SARS-CoV-2 and the importance of identifying the true epidemiology of adverse outcomes regarding promoting increased acceptance of COVID-19 vaccinations, while stressing that despite the possibility of adverse outcomes, the benefits of vaccination outweigh the risks of remaining unvaccinated.