Herein, we established the proof of the concept of internal flow choking in CVS causing cardiovascular risk through the closed-form analytical, in vitro and in silico methods. An over dose of blood-thinning drug will enhance the Reynolds number, which creates high turbulence level causing an augmented boundary layer blockage factor leading to an early undesirable biofluid/Sanal flow choking at a critical blood-pressure-ratio (BPR). The fact is that in nanoscale vessels when the pressure of fluid increases, average-mean-free-path decreases and thus, the Knudsen number reduces. It leads to the physical situation of no-slip boundary condition with compressible-viscous flow effect. Sanal-flow-choking is a compressible-viscous flow effect establishing a physical condition of the sonic-fluid-throat, at a critical blood pressure ratio (BPR). We concluded that asymptomatic-hemorrhage (AH) and acute-heart-failure (AHF) are transient-events as a result of internal flow-choking in nanoscale and/or large vessels followed by the shock wave creation and transient pressure-overshoot. We concluded that cardiovascular risk could be reduced by simultaneously lessening the blood-viscosity and flow turbulence by increasing thermal-tolerance-level in terms of BHCR and/or by decreasing the blood pressure (BP) ratio.