A method of detecting a dislodged needle in a hemodialysis procedure includes measuring venous drip pressure of the dialysis machine of a patient undergoing hemodialysis, analyzing the venous drip pressure and deriving intravascular blood pressure at a location of venous needle insertion into the patient, comparing the derived intravascular blood pressure to a standard, repeating the measuring, analyzing and deriving, and comparing steps and, if the intravascular blood pressure is within a specified range of the standard, determining that a needle has been dislodged in the hemodialysis procedure. A method of alerting the patient and medical personnel of a dislodged needle in a hemodialysis procedure includes detecting a drop in intravascular pressure derived from measured venous drip pressure, determining that a needle is dislodged, and alerting medical personnel of the dislodged needle.