The human blood proteome provides a holistic readout of health states through the assessment of thousands of circulating proteins. Here, we present a pan-disease resource to enable the study of diverse disease phenotypes within a harmonized proteomics dataset. By profiling protein concentrations across 59 diseases and healthy cohorts, we identified proteins associated with age, sex, and BMI, as well as disease-specific signatures. This study highlights shared and distinct protein patterns across conditions, demonstrating the power of a unified proteomics approach to uncover biological insights. The dataset, covering 8,262 individuals and up to 5,416 proteins, serves as an online resource for exploring disease-specific protein profiles and advancing precision medicine research.