1. An ultrasound measurement apparatus comprising: a probe that is configured to transmit an ultrasonic wave to a blood vessel and receive a reflected wave from the blood vessel; a processor that is configured to: track a position of a vascular wall of the blood vessel in a biological tissue on the basis of the reflected wave; measure a displacement velocity in a positive direction and a displacement velocity in a negative direction of the vascular wall; and determine whether or not the blood vessel to be tracked is an artery based on a relative relationship between the displacement velocity in the positive direction and the displacement velocity in the negative direction, and determine that the blood vessel to be tracked is the artery when the displacement velocity in the positive direction and the displacement velocity in the negative direction satisfy a predetermined condition; and a display that displays the determination result.