A load abnormality detection apparatus detects a load abnormality in first and second rotational members acting on each other. An inclination calculation part calculates an inclination of a second control element. A first comparison part compares a first control element with a first threshold value and also with a second threshold value larger than the first threshold value. A second comparison part compares an inclination of change in the second control element with a third threshold value of a negative value and also with a fourth threshold value of a positive value. An abnormality detection part detects a load abnormality in a load applied to the first rotational member and the second rotational member based on results of comparison by the first comparison part and the second comparison part and identifies a cause of the detected load abnormality.