Auto-inflammatory diseases cannot be equated with the familiar autoimmune diseases. Auto-inflammatory diseases are a group of rare inherited periodic diseases that cause systemic inflammation due to mutations in the genes that encode proteins that lead to dysregulation of intrinsic immunity. Due to their genetic characteristics, most autoinflammatory diseases have an early onset, with a few developing in adulthood. The clinical picture is one of recurrent systemic inflammation, with the majority of patients presenting with sudden onset of periodic fever, rash, pluritis, lymph node enlargement and arthritis with elevated acute phase reactants. In the asymptomatic interictal phase, the patient’s health and growth are as normal and the acute phase reactants are completely normal. Auto-inflammatory diseases include a group of monogenic genetic disorders, but also some polygenic disorders. Autoimmune diseases include a large group of diseases that can involve various tissues and organs, usually referred to mainly as diffuse connective tissue diseases. Depending on the main pathological and clinical features, autoimmune diseases are often divided into two main groups of diseases: multi-organ (systemic) diseases and single organ (tissue) involvement diseases. Autoimmune diseases are caused by the production of large amounts of autoantibodies against autoantigens such as DNA, cell surface molecules and intracellular proteins. The etiology of autoimmune diseases is unknown, and both genetic and environmental factors may be involved, but the hyperreactivity of the adaptive immune system against autoantigens plays a major role. The relationship between auto-inflammatory diseases and autoimmune disorders has been gaining attention in recent years. Preliminary studies have revealed many similarities between auto-inflammatory diseases and autoimmune diseases, such as: both have the prefix “self”, indicating that their pathological processes are directed against their own tissues; both are systemic diseases, mainly involving the skin and musculoskeletal system; both include both monogenic and polygenic diseases; and from a pathophysiological point of view, both are systemic diseases, mainly involving the skin and musculoskeletal system. From a pathophysiological point of view, both involve chronic activation of the immune system in certain genetically susceptible individuals, ultimately leading to tissue inflammation. However, there are also a number of differences between the two groups of diseases. For example, auto-inflammatory diseases are due to direct tissue inflammation by the intrinsic immune system, whereas autoimmune diseases are due to activation of the adaptive immune system by the intrinsic immune system, which triggers the inflammatory process; auto-inflammatory diseases usually do not have autoantibodies or antigen-specific T cells, and it is mainly mononuclear macrophages, not T and B cells, that are involved in the inflammatory damage process. And as research progresses, a new view is becoming accepted that auto-inflammatory diseases and autoimmune diseases are more likely to belong to the same spectrum of diseases with a large set of clinical manifestations, with pure auto-inflammatory diseases at one end and pure autoimmune diseases at the other, while those diseases that do not quite fit either pure manifestation may belong to intermediate cross-types or transitional types.