Nearly half of the global population are carriers of ( ), a Gram-negative bacterium that persists in the healthy human stomach. can be a pathogen and causes development of peptic ulcer disease in a certain state of the macroorganism. It is well established that infection is the main cause of chronic gastritis and peptic ulcer disease (PUD). Decontamination of the gastric mucosa with various antibiotics leads to elimination and longer remission in this disease. However, the reasons for repeated detection of in recurrent PUD after its successful eradication remain unclear. The reason for the redetection of in recurrent PUD can be either reinfection or ineffective anti-Helicobacter therapy. The administration of antibacterial drugs can lead not only to the emergence of resistant strains of microorganisms, but also contribute to the conversion of into the resting (dormant) state. The dormant forms of have been shown to play a potential role in the development of relapses of PUD. The paper discusses morphological forms, such as S-shaped, C-shaped, U-shaped, and coccoid ones. The authors proposes the classification of according to its morphological forms and viability.