Abstract: Methods and devices for detecting thrombin generation are disclosed. Generally, the methods include combining a blood sample with a reagent composition so that reaction of the reagent composition and thrombin, if present in the sample, produces a detectable signal; and detecting the detectable signal. Generally, the devices include a fluid-tight material forming at least one passageway; a first chamber in fluid communication with at least one passageway; and at least one reagent disposed on a surface of or contained in either a chamber or a passageway. In some embodiments, the passageway is configured to permit capillary flow of fluid, while in other embodiments, fluid flow is accomplished through a pump functionally linked to at least one passageway. In some embodiments, the device may further include a signal detector positioned to detect a signal generated in a chamber or passageway. In certain embodiments, the device may further include a microprocessor functionally linked to the signal detector.