A system comprising: a plurality of electrodes and/or one or more optical sensors for detecting at least one signal associated with pulse transit times; accelerometer circuitry configured to generate at least one signal; a memory; and processing circuitry coupled to the accelerometer circuitry and the memory, the processing circuitry being configured to: determine, by using the at least one signal associated with pulse transit times, a first plurality of pulse transit times of a patient prior to a Sit-to-Stand transition of the patient ; determine, based on the at least one accelerometer signal, whether the Sit-to-Stand transition of the patient occurs; determine, based on the Sit-to-Stand transition occurring and by using the at least one signal associated with pulse transit times, a second plurality of pulse transit times after the Sit-to-Stand transition of the patient ; and determine a likelihood the patient will fall based on the first plurality of pulse transit times and the second plurality of pulse transit times; wherein the processing circuitry is configured to determine the likelihood the patient will fall at least in part by calculating a first metric based upon the first plurality of pulse transit times; and wherein the processing circuitry is further configured to determine the likelihood the patient will fall at least in part by calculating second metrics based on the second plurality of pulse transit times. a plurality of electrodes and/or one or more optical sensors for detecting at least one signal associated with pulse transit times; accelerometer circuitry configured to generate at least one signal; a memory; and processing circuitry coupled to the accelerometer circuitry and the memory, the processing circuitry being configured to: determine, by using the at least one signal associated with pulse transit times, a first plurality of pulse transit times of a patient prior to a Sit-to-Stand transition of the patient ; determine, based on the at least one accelerometer signal, whether the Sit-to-Stand transition of the patient occurs; determine, based on the Sit-to-Stand transition occurring and by using the at least one signal associated with pulse transit times, a second plurality of pulse transit times after the Sit-to-Stand transition of the patient ; and determine a likelihood the patient will fall based on the first plurality of pulse transit times and the second plurality of pulse transit times; wherein the processing circuitry is configured to determine the likelihood the patient will fall at least in part by calculating a first metric based upon the first plurality of pulse transit times; and wherein the processing circuitry is further configured to determine the likelihood the patient will fall at least in part by calculating second metrics based on the second plurality of pulse transit times. determine, by using the at least one signal associated with pulse transit times, a first plurality of pulse transit times of a patient prior to a Sit-to-Stand transition of the patient ; determine, based on the at least one accelerometer signal, whether the Sit-to-Stand transition of the patient occurs; determine, based on the Sit-to-Stand transition occurring and by using the at least one signal associated with pulse transit times, a second plurality of pulse transit times after the Sit-to-Stand transition of the patient ; and determine a likelihood the patient will fall based on the first plurality of pulse transit times and the second plurality of pulse transit times; wherein the processing circuitry is configured to determine the likelihood the patient will fall at least in part by calculating a first metric based upon the first plurality of pulse transit times; and wherein the processing circuitry is further configured to determine the likelihood the patient will fall at least in part by calculating second metrics based on the second plurality of pulse transit times. <EOS>