Abstract:The emergence of immunotherapy in recent years has revolutionized traditional cancer treatment. Immunotherapy is just an immunosuppressant that regulates immune checkpoints. Immunosuppressive agents include cytotoxic T lymphocyte antigen-4 (CTLA-4) inhibitors, programmed cell death-1 (PD-1) inhibitors and programmed cell death ligand-1 (PD-L1) inhibitor. PD-1 / PD-L1 agents are involved in the maintenance of immune tolerance to autoantigens by blocking the PD-1 / PD-L1 pathway to regulate important inhibitory pathways of immune tolerance. However, a shift in the balance of the immune system can also develop immune-related adverse events (irAEs) in multiple tissues and organs. IrAEs differ from traditional chemotherapeutic drugs or the side effects of targeted therapies, and currently have relatively little experience in their diagnosis and management. Therefore, irAEs constitute a real challenge in immunotherapy, and any further changes may be related to treatment. The most common irAEs occurs in the skin, the gastrointestinal tract, attended by the lungs, endocrine system, musculoskeletal, kidney, nerve, blood, and cardiovascular. IrAEs are usually transient and controllable, but can sometimes lead to disruption of immunotherapy and may even cause fatal adverse events (FAE). This article is a review of current irAEs produced by PD-1 inhibitors.