Coronavirus infectious Disease 2019 (COVID-19) was first reported in Wuhan, China, with its multiple variants became a global concern. In response to the pandemic, intensive research and development efforts were undertaken by scientists in collaboration with pharmaceutical companies to develop six COVID-19 vaccines approved by World Health Organization (WHO). Coronavirus divided into 4 different genera: alpha, beta, gamma and delta virus. Due to its unstable ssRNA; there are many strains which have become more transmissible than pre-existing strain. To write this systemic review paper; we followed guidelines of Cochrane Handbook for a systematic review and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Total of 12 eligible studies were included in the review. All of the studies included in this review reported on syndromes experienced by patients following COVID-19 infection. Syndromes reported in the literature include immune thrombocytopenic purpura (ITP), viral encephalomyelitis, hemophagocytic lymphohistiocytosis, thrombotic thrombocytopenic purpura (TTP), Guillain-Barrè syndrome and postural orthostatic tachycardia syndrome (POTS). Each syndrome is discussed with the hypothesized pathophysiology, the presented symptoms and treatment executed. This systemic review paper discusses coronavirus and its variants in the introduction to provide general view of the virus then looks into the syndromes reported to occur after COVID-19 infection.