Embodiments of the present disclosure relate to a system and method for determining a risk, onset, or presence of hypovolemia based on one or more features of a plethysmographic waveform during a patient breathing cycle. For example, a hypovolemic patient may exhibit characteristic changes in pulse amplitude or stroke volume during inhalation and exhalation relative to a healthy patient. Further, a trend or pattern of such features may be used to assess the patients fluid condition.
