Systems and methods for determining and communicating levels of bilirubin and other subcutaneous substances

A system including a computing device, a software application stored in a memory of the computing device and configured to run on a processor of the computing device, and a module in communication with the computing device, said module including a data communication capability, where the data includes light intensity or wavelength information, a light source configured to provide light capable of penetrating the patient's skin to a subcutaneous level, a light sensor configured to detect the light from the light source reflected and scattered from the patient's skin including from the subcutaneous level at a single point in time or sequentially at multiple points in time, and a power source, where the software application is configured to determine levels or concentrations of a substance in a patient's skin based on a measurement of light intensity or wavelength from the light sensor.