Recurrent aphthous stomatitis is a polyetiological inflammatory disease of the oral mucosa, characterized by the appearance of aphthous ulcers. The etiology and pathogenesis of this disease have not been finally revealed. There is an imbalance of immunity observed in patients who are suffering from recurrent aphthous stomatitis caused by the influence of certain trigger factors. The purpose is to summarize the literature data on the relationship of somatic status with the occurrence of recurrent aphthous stomatitis. The review considers the pathogenesis of recurrent aphthous stomatitis, as well as possible trigger factors: genetic predisposition, infections, somatic diseases, allergies, stress, and hypovitaminosis. An obligatory link in the pathogenesis of recurrent aphthous stomatitis is an imbalance of immunity - cellular (the production of pro-inflammatory cytokines increases, and the synthesis of anti-inflammatory heat shock proteins decreases) and humoral (an increase in the number of neutrophils and B-lymphocytes, activation of the complement system). Genetic predisposition, some somatic diseases (Behcet's disease) and viral infections (in particular, COVID-19) lead to an imbalance in the immune system. Provoke the occurrence of recurrent aphthous stomatitis infections, diseases of the gastrointestinal tract, stress and insufficiency of B vitamins and trace elements. The indirect effect of trigger circumstances is due to a decrease in the trophism of the oral mucosa, which leads to a local decrease in the number of factors of cellular and humoral immunity and to hyposalivation and a decrease in the pH of the oral fluid, which provokes the reproduction of opportunistic microflora. Based on the analyzed literature data, it can be concluded that the somatic status influences the development of recurrent aphthous stomatitis. Accordingly, patients suffering from recurrent aphthous stomatitis should be referred to a general doctor for evaluation.