This paper presents a hand-held point-of-care diagnostic device that incorporates a lab-on-a-chip module with interdigitated capacitive biosensors for label-free detection of multiple cancer and cardiovascular disease biomarkers. The developed prototype is comprised of a capacitive bio-detection chip, a sensitive capacitive readout electronics enclosed in a hand-held unit and a data analysis software calculating the quantity of biomarkers using previously stored reference database for different concentrations of each biomarker. The capacitive bio-detection chip is based on interdigitated circular electrodes, which are pre-activated with single (for detecting one biomarker) or multiple specific antibodies (for detecting multiple disease biomarkers). Detection principle of capacitive biosensor is based on measuring the level of capacitance change between interdigitated electrode pairs of the capacitive biosensor chip induced by the change in dielectric constant due to affinity-based electron exchange in between antibodies and antigens. The more antibody-antigens binding occurs, the more capacitance change is measured due to the change in dielectric constant of the capacitance media. The device uses pre-activated ready-to-use cartridges, composed of capacitive biosensors, which can be stored 3 months under optimal conditions, and is capable of on-site diagnosis and can report the result in less than 30 minutes. The device is verified with 16 real patient blood samples for 6 different disease biomarkers.