A blood pressure decrease prediction device is provided with: a pulse count calculation unit (110) for calculating the pulse count of an organism on the basis of blood flow waveforms expressing the change over time in the volume of blood flow in an organism; a blood flow volume calculation unit (120) for calculating the volume of blood flow in an organism on the basis of the blood flow waveforms; a pulse wave amplitude calculation unit (130) for calculating the pulse wave amplitude in an organism on the basis of the blood flow waveforms; and a blood pressure decrease prediction unit (140) for predicting a decrease in blood pressure, on the basis of the fluctuations in the calculated pulse count, the calculated blood flow volume, and the calculated pulse wave amplitude.
