A mobile device for detecting blood pressure comprising: a display unit; a camera; a sensing unit coupled to the outside of the housing, wherein the sensing unit includes a photoplethysmography sensor configured to measure blood volume oscillations, a pressure sensor configured to measure an applied pressure value; a non-transitory computer-readable medium that stores instructions that, when executed by a processor, cause the processor to: display, on a graphical user interface of the device, a target pressure graph to guide a user to steadily increase an applied pressure with a finger of the user; measure the applied pressure over a predetermined period of time using the pressure sensor; measure the blood volume oscillations using the PPG sensor; generate an oscillogram based on the blood volume oscillations and the applied pressure; calculate a blood pressure value based on the oscillogram; and display, on the GUI of the device, the blood pressure value, characterized in that the non-transitory computer-readable medium further stores instructions that, when executed by the processor, cause the processor to record, by the camera, an image of the face of the user and to compare the image to a previously recorded image of the face of the user known to be recorded at heart level, and if it is detected that the device is not being held at heart level, adjusting the blood pressure value for the height at which the measurements were being taken using a rho-g-h correction, where rho is the known blood density, g is gravity, and h is the vertical distance between the finger and heart estimated from the images. a display unit; a camera; a sensing unit coupled to the outside of the housing, wherein the sensing unit includes a photoplethysmography sensor configured to measure blood volume oscillations, a pressure sensor configured to measure an applied pressure value; a non-transitory computer-readable medium that stores instructions that, when executed by a processor, cause the processor to: display, on a graphical user interface of the device, a target pressure graph to guide a user to steadily increase an applied pressure with a finger of the user; measure the applied pressure over a predetermined period of time using the pressure sensor; measure the blood volume oscillations using the PPG sensor; generate an oscillogram based on the blood volume oscillations and the applied pressure; calculate a blood pressure value based on the oscillogram; and display, on the GUI of the device, the blood pressure value, characterized in that the non-transitory computer-readable medium further stores instructions that, when executed by the processor, cause the processor to record, by the camera, an image of the face of the user and to compare the image to a previously recorded image of the face of the user known to be recorded at heart level, and if it is detected that the device is not being held at heart level, adjusting the blood pressure value for the height at which the measurements were being taken using a rho-g-h correction, where rho is the known blood density, g is gravity, and h is the vertical distance between the finger and heart estimated from the images. display, on a graphical user interface of the device, a target pressure graph to guide a user to steadily increase an applied pressure with a finger of the user; measure the applied pressure over a predetermined period of time using the pressure sensor; measure the blood volume oscillations using the PPG sensor; generate an oscillogram based on the blood volume oscillations and the applied pressure; calculate a blood pressure value based on the oscillogram; and display, on the GUI of the device, the blood pressure value, characterized in that the non-transitory computer-readable medium further stores instructions that, when executed by the processor, cause the processor to record, by the camera, an image of the face of the user and to compare the image to a previously recorded image of the face of the user known to be recorded at heart level, and if it is detected that the device is not being held at heart level, adjusting the blood pressure value for the height at which the measurements were being taken using a rho-g-h correction, where rho is the known blood density, g is gravity, and h is the vertical distance between the finger and heart estimated from the images.