The term used for anticipating discomfort about future events is:

The term "anxiety" specifically refers to the emotional response characterized by feelings of apprehension or worry about potential future events that may lead to discomfort. It encompasses a broad range of responses, from mild unease to intense fear, often arising from anticipation of negative outcomes. Anxiety can manifest as physical symptoms as well, such as increased heart rate or sweating, as the individual may experience tension or unease regarding uncertain situations.

In contrast, "fear" typically relates to a direct and immediate threat, while "concern" conveys a broader sense of care or interest about an issue but does not necessarily involve the same level of emotional intensity or physical response. "Confidence" represents a sense of certainty or assurance in oneself or the outcome of an event, which is the opposite of the anticipatory discomfort described in the question. Therefore, "anxiety" is the appropriate term as it effectively captures the essence of worrying about potential discomfort in the future.