Blood leakage and blood loss are serious life-threatening complications occurring during dialysis therapy. these events have been of concerns to both healthcare givers and patients. more than 40% of adult blood volume can be lost in just a few minutes, resulting in morbidities and mortality. this paper describes the application of photo detector installed in a blood leakage monitoring system to detect blood leakage during hemodialysis treatment. our system consists of auto/manual mode. in auto mode, the blood flow will be controlled based on heart sensor & blood pressure automatically and its monitored in the cayenne app. nurse/doctor can vary the blood flow remotely with help of iot module in the manual mode of operation. photocell sensors are arranged in a flexible substrate to detect blood leakage via the resistance changes with illumination in the visible spectrum. the signal received by the sensor is calibrated for the output which sensing the blood’s color only. this system consists of an ldr sensor, microcontroller, iot module and alert components. the red color sensing algorithm is simply evaluated on the microcontroller. the goal of this system is to give alarm when the sensor senses the red color only. so if blood leak occur on the arterio-venous fistula, it can be detected during hemodialysis treatment. this system also transmits the blood leak occurrence to nurse and relative’s mobile phone and appropriate alerts are taken immediately by the healthcare workers to prevent any risk happen to the patient during hemodialysis therapy.