obsolete_blood viscosity true MESH:D001809 3.74.0 http://purl.obolibrary.org/obo/OBA_VT3000004 Project to replace EFO measurement branch with enriched OBA branch. Please use: OBA:VT3000004 SNOMEDCT:85015001 Dani Welter The internal resistance of the BLOOD to shear forces. The in vitro measure of whole blood viscosity is of limited clinical utility because it bears little relationship to the actual viscosity within the circulation, but an increase in the viscosity of circulating blood can contribute to morbidity in patients suffering from disorders such as SICKLE CELL ANEMIA and POLYCYTHEMIA.