VEHICLE HEADLIGHT AND VEHICLE HEADLIGHT SYSTEM

A vehicle headlight (1) includes a light emitting unit (10), a determination unit (25), and a control unit (CO). The control unit (CO) controls the light emitting unit (10) such that, when a signal indicating another vehicle (80, 90) is input, a region including a first region (211, 311) in a light distribution pattern (200, 300) becomes a light reduction region (210, 310) in which a total light flux amount of light from the light emitting unit (10) decreases as compared with that before the signal indicating the other vehicle (80, 90) is input, and controls the light emitting unit (10) such that, when a signal indicating a turn sign of the other vehicle (80, 90) is input, at least the first region (211, 311) in the light reduction region (210, 310) expands to a turning direction side indicated by the turn sign as compared with that before the signal indicating the turn sign of the other vehicle (80, 90) is input.