Devices and methods are described for a hand-held hydration monitor including a viewfinder including one or more alignment features configured to align with a target on a subject; a micro-impulse radar component; a data storage component including stored information associated with reference reflected pulses correlated with reference hydration states; a user interface; and a computing component including a processor and circuitry, the circuitry including micro-impulse radar control circuitry configured to actuated the micro-impulse radar component, and hydration determination circuitry configured to receive information associated with one or more reflected pulses from a tissue associated with the target on the subject and to compare the information associated with the one or more reflected pulses from the tissue associated with the target on the subject with the stored information associated with the reference reflected pulses correlated with the reference hydration states to determine a relative hydration state of the tissue.