The COVID-19 pandemic created uncertainty about our health and lives, and people were scared and looking for information to make themselves less likely to get infected. Yet, much information spread on the Internet may not be true. Before the pandemic, fake news, misinformation, and disinformation about public health (i.e., false health information) were found spreading on social media. Due to the citizens’ lack of trust in their governments in many countries, people were more likely to believe in such false health information. This research proposed a conceptual model for understanding factors influencing false health information formation by reviewing recent literature on spreading fake news and misinformation about health information from health science and social science disciplines. We focused on understanding how it spread during and after the COVID-19 pandemic and how it affected people’s perceptions of believing and not believing the information disseminated on social media by different stakeholders (i.e., government departments, public health authorities, etc.). Our findings provided a clear understanding of potential factors influencing the spreading of false health information and helped researchers and stakeholders understand how false health information spreads. It set the foundations for future research on this research area, including but not limited to studying factors making people believe in false information, factors making people alert to false information, and factors that strengthen or weaken those effects, and developing policy recommendations for how we can minimize the impact of false health information on our society and others.