1. A method comprising, by one or more processors associated with one or more computing devices: accessing, by one or more of the processors, one or more data streams from a plurality of sensors, the sensors comprising a renal Doppler sonograph and one or more of a heart-rate monitor, a blood-pressure monitor, a pulse oximeter, or a mood sensor, the data streams comprising renal-Doppler data of a person from the renal Doppler sonograph and one or more of heart-rate data of the person from the heart-rate monitor, blood-pressure data of the person from the blood-pressure monitor, pulse-oximetry data of the person from the pulse oximeter, or self-reported mood data of the person from the mood sensor; and generating, by one or more of the processors, a stress model of the person based on the data streams, the stress model comprising baseline renal-Doppler data of the person, and one or more of baseline heart-rate data of the person, baseline blood-pressure data of the person, baseline pulse-oximetry data of the person, or baseline self-reported mood data of the person, wherein the baseline renal-Doppler data measures a stress response of the sympathetic nervous system of the person, and wherein the stress model correlates the baseline renal-Doppler data of the person with one or more of the baseline heart-rate data of the person, the baseline blood-pressure data of the person, the baseline pulse-oximetry data of the person, or the baseline self-reported mood data of the person.