Respiratory illnesses like Influenza virus (flu), COVID-19, and Respiratory Syncytial Virus (RSV) spread easily in fall and winter, when people spend more time together indoors. These illnesses affect your respiratory system and therefore your breathing. When multiple viruses are spreading, it can strain the healthcare system and make it harder to access care for other issues, as well. Please click here to view and download a respiratory illnesses handout fromthe Snohomish County Health District.