An alert information presenting apparatus includes an undressing condition determiner that determines, by using a movement speed of the user, a second time period indicating a time period before undressing, and a third time period indicating a time period after undressing, a heartbeat acquirer that acquires a heartbeat timing in the second time period and a heartbeat timing in the third time period, a pulse wave acquirer that acquires a pulse wave timing in the second time period and a pulse wave timing in the third time period, a blood pressure calculator that calculates a pre-undressing blood pressure by using a pre-undressing heartbeat timing and a pre-undressing pulse wave timing, and calculates a post-undressing blood pressure by using a post-undressing heartbeat timing and a post-undressing pulse wave timing, and an information presenter that presents the user with alert information based on a difference between the pre-undressing and post-undressing blood pressures.