A bodily fluid processing system for monitoring fluid flow in a medical fluid procedure using hydrostatic pressure, comprising: a hardware component controlled by a programmable controller, a fluid circuit comprising a plurality of fluid pathways configured to mount and associate with the hardware component, wherein the hardware component comprises a pressure sensor (PS, PS1, PS2, PS3, PS4) in communication with the programmable controller and a fluid pathway; the fluid circuit includes a container (12, 18, 41, 41a, 62) configured for fluid communication with the pressure sensor (PS, PS1, PS2, PS3, PS4) and configured to receive a volume of a fluid; and the controller is configured to: initiate a phase of the medical fluid procedure associated by the controller with a plurality of ranges of pressure values authorized at specific times for the pressure sensor (PS, PS1, PS2, PS3, PS4); receive a first pressure value from the pressure sensor (PS, PS1, PS2, PS3, PS4) measured at a first time, when the container (12, 18, 41, 41a, 62) is not in fluid communication with the pressure sensor (PS, PS1, PS2, PS3, PS4); receive a second pressure value from the pressure sensor (PS, PS1, PS2, PS3, PS4) measured at a second time, when the container (12, 18, 41, 41a, 62) is in fluid communication with the pressure sensor, with the second pressure value being indicative of hydrostatic pressure applied by the fluid within the container (12, 18, 41, 41a, 62) and the fluid pathway; compare a difference between the second pressure value and the first pressure value to an authorized range of pressure values; and execute a response action if the difference is not within the authorized range of pressure values. a hardware component controlled by a programmable controller, a fluid circuit comprising a plurality of fluid pathways configured to mount and associate with the hardware component, wherein the hardware component comprises a pressure sensor (PS, PS1, PS2, PS3, PS4) in communication with the programmable controller and a fluid pathway; the fluid circuit includes a container (12, 18, 41, 41a, 62) configured for fluid communication with the pressure sensor (PS, PS1, PS2, PS3, PS4) and configured to receive a volume of a fluid; and the controller is configured to: initiate a phase of the medical fluid procedure associated by the controller with a plurality of ranges of pressure values authorized at specific times for the pressure sensor (PS, PS1, PS2, PS3, PS4); receive a first pressure value from the pressure sensor (PS, PS1, PS2, PS3, PS4) measured at a first time, when the container (12, 18, 41, 41a, 62) is not in fluid communication with the pressure sensor (PS, PS1, PS2, PS3, PS4); receive a second pressure value from the pressure sensor (PS, PS1, PS2, PS3, PS4) measured at a second time, when the container (12, 18, 41, 41a, 62) is in fluid communication with the pressure sensor, with the second pressure value being indicative of hydrostatic pressure applied by the fluid within the container (12, 18, 41, 41a, 62) and the fluid pathway; compare a difference between the second pressure value and the first pressure value to an authorized range of pressure values; and execute a response action if the difference is not within the authorized range of pressure values. the fluid circuit includes a container (12, 18, 41, 41a, 62) configured for fluid communication with the pressure sensor (PS, PS1, PS2, PS3, PS4) and configured to receive a volume of a fluid; and the controller is configured to: initiate a phase of the medical fluid procedure associated by the controller with a plurality of ranges of pressure values authorized at specific times for the pressure sensor (PS, PS1, PS2, PS3, PS4); receive a first pressure value from the pressure sensor (PS, PS1, PS2, PS3, PS4) measured at a first time, when the container (12, 18, 41, 41a, 62) is not in fluid communication with the pressure sensor (PS, PS1, PS2, PS3, PS4); receive a second pressure value from the pressure sensor (PS, PS1, PS2, PS3, PS4) measured at a second time, when the container (12, 18, 41, 41a, 62) is in fluid communication with the pressure sensor, with the second pressure value being indicative of hydrostatic pressure applied by the fluid within the container (12, 18, 41, 41a, 62) and the fluid pathway; compare a difference between the second pressure value and the first pressure value to an authorized range of pressure values; and execute a response action if the difference is not within the authorized range of pressure values. initiate a phase of the medical fluid procedure associated by the controller with a plurality of ranges of pressure values authorized at specific times for the pressure sensor (PS, PS1, PS2, PS3, PS4); receive a first pressure value from the pressure sensor (PS, PS1, PS2, PS3, PS4) measured at a first time, when the container (12, 18, 41, 41a, 62) is not in fluid communication with the pressure sensor (PS, PS1, PS2, PS3, PS4); receive a second pressure value from the pressure sensor (PS, PS1, PS2, PS3, PS4) measured at a second time, when the container (12, 18, 41, 41a, 62) is in fluid communication with the pressure sensor, with the second pressure value being indicative of hydrostatic pressure applied by the fluid within the container (12, 18, 41, 41a, 62) and the fluid pathway; compare a difference between the second pressure value and the first pressure value to an authorized range of pressure values; and execute a response action if the difference is not within the authorized range of pressure values.