The corona virus invades cells by binding to the so-called angiotensin converting enzyme-2 (ACE-2). High blood pressure has been shown to be a high risk factor for serious complications and death from COVID-19 infection. The aim of the project is to confirm or disprove the theory that the use of two commonly used types of antihypertensive drugs (angiotensin converting enzyme inhibitors (ACE inhibitors) and angiotensin receptor blockers (ARBs)) is associated with increased risk of COVID-19 infection and COVID-19 complications that require hospitalization, intensive care, respiratory care or death. Pseudonymized data will be obtained from Norwegian health registries (the Prescription Register, the Reporting System for Infectious Diseases, the Pandemic Register and the Norwegian Intensive Care Register). We will compare the risk of COVID-19 infection and COVID-19 complications requiring hospitalization, admission to an intensive unit, respiratory care or death in users with non-users of ACE inhibitors and ARBs in the adult Norwegian population. We will adjust the statistical analyzes for relevant confounding factors. The usefulness of the project is very high because there is great uncertainty around the world about the use of ACE inhibitors and ARB is associated with increased risk of COVID-19. More than 600,000 Norwegians used these medicines in 2018. The effects of quitting blood pressure medicine are also potentially great. It is therefore of the utmost importance to quickly clarify whether the use of ACE inhibitors and ARBs is associated with increased risk of COVID-19.