Does bed bugs have any health impact? i know they r harmless except skin rash & potential skin infection but they live on human blood so my question is does the blood lost has any negative/positive health impact? does small blood loss actually helps?

Bed bugs: Blood loss in this quantity won't have an impact. Although there is no evidence that Bed bugs (Cimex lectularius) act as a vector for transmitting infectious diseases to humand, there are studies that suggest it might transmit Trypanosoma cruzi (Chaga Disease). REF: https://entomologytoday.org/2018/01/30/study-further-evidence-bed-bugs-transmit-chagas-disease-pathogen/