Stress is the result of an unmet expectation. The word "tension" implies there are two points that are at odds with each other. Imagine a rope and you are holding onto to one end; the other end is tied to a stake in the ground. The rope is your thought about how something should be, and the stake is your belief in that thought that is not supported in your reality. Yoga teaches that thoughts aren't the problem but rather our attachments to those thoughts, essentially our beliefs. You may have realized by now that you cannot change people. Ghandi has a great quote that is timeless, "Be the change you want to see in the world". How about, be the change you want to see at work.
For many, the workplace is the greatest source of stress so begin noticing the relationship between thoughts and your beliefs about those thoughts. Apply "The Work" to your beliefs in order to realize, experientially, that these beliefs are not supported by reality. By practicing self-enquiry, yoga and meditation we can become more aware of this connection between thought and belief. Believing every thought that passes through your head is a recipe for stress and suffering. A student once asked a meditation master about the difference between the student's mind and the mind of the master, the Master replied, "thoughts that arise in this mind are like clouds passing through the sky".
Each time you feel the contractions or tightening characteristic of stressful moments, explore the thoughts and your belief about those thoughts that lead to that internal reaction. Practice is the key and withdrawing your expectations of reality in favor of being with your reality. The difference is subtle but profound.