Abstract Diagnosis of von Willebrand disease (VWD) is a challenge due to variability in laboratory assays, variability in patient von Willebrand factor (VWF) levels, and variability in the different types of VWD. Because of these challenges, it can be difficult to make the diagnosis, especially in young children. On the other hand, older individuals may carry a diagnosis of VWD and not truly have VWD, creating the necessity for thoughtful evaluation of patients for whom “undiagnosing” VWD is appropriate. The most important factor is clinical bleeding history, although repeated laboratory testing and individual considerations are also critical. More research is needed on aging and VWF to best understand this challenge.