A surgical mask, also known as a medical face mask, is a personal protective equipment worn by health professionals during medical procedures[1][2] to prevent airborne transmission of infections between patients and/or treating personnel, by blocking the transmission of pathogens (primarily bacteria and viruses) shed in respiratory droplets and aerosols from the wearer’s mouth and nose.[3][4][5] They act as an additional barrier for the airway and are not usually designed (unless N95-rated) to completely prevent the wearer from inhaling smaller airborne pathogens, but could be still protective by filtering out and trapping most of the droplets that carry them.[6] There is a predominance of evidence that surgical masks protect both the wearer (by filtering the inhaled air) and bystanders (by blocking down forceful exhalations from the wearer that can spread pathogens afar).[7]
