Techniques and apparatuses for determining fluid volumes of a patient are described. In one embodiment, for example, an apparatus may include at least one memory, and logic coupled to the at least one memory. The logic may be configured to receive baseline bioimpedance information for at least a portion of a human body at a baseline pressure, receive pressurized bioimpedance information of the portion of the human body at a pressurized pressure, the pressurized pressure greater than the baseline pressure and configured to substantially remove blood volume from the portion at the pressurized pressure, and determine at least one of interstitial fluid volume (V
