Tension rarely pays dividends. In fact, it usually yields negative outcomes - damaged relationships, compromised health, reduced productivity. Unlike focus and intensity (both good states), tension puts us in a state of strain, emotionally and/or physically.
More often than not we experience tension when things get out of control, or better stated, out of our control. When we let ourselves drift into a state of tension, it has absolutely no effect on the circumstances. What the tension does do, however, is negatively impact our ability to think, to perform, and to use sound judgment.
Those of us who work with others experience conflict on a regular basis. It's just part of the deal when interacting with other humans. When we allow ourselves to become tense, even in the midst of conflict, we are less effective and more likely to say/do things we'll regret later.
Even when circumstances seem to spin out of (our) control, we can and should remain calm, clear-headed, and focused.
It's a learnable skill, and anything less makes us less.