Any Condition Underlying Critical Illness

The goal of this observational study is to understand the genetic and molecular risk factors for developing critical illness in adult intensive care unit (ICU) patients in Sweden. The main questions it aims to answer are: Which genetic variants are associated with increased risk of critical illness from conditions such as infections, sepsis, and organ failure? Can circulating proteins and metabolites mediate the effect of genetic risk factors on the severity of illness? Participants will: Provide blood samples at ICU admission and again 3-6 months after discharge Consent to genetic analysis and data linkage with national health registries Have their ICU treatment and outcomes followed using registry and clinical data This study aims to build a national infrastructure for rapid sample collection and analysis that can also support research in future pandemics.