Stress
You've got stress bombarding you from a couple of directions. First, you want your athletes to stay healthy and uninjured so they can keep playing. Unfortunately, you don't control their off-the-field activity, which means they're free to engage in all sorts of self-destructive behaviors.
The bottom line, however, is that you're trying to produce a desired effect when you can't control all the variables. That's got to make you gnaw your fingernails. If you work on the pro sports level, you might be close to a basket case, since those athletes have more disposable income and a lot more ways to get themselves in trouble.
Now imagine how your stress level skyrockets when one of your athletes gets injured. You're the first one to examine him on the field or in the locker room. You'll probably order additional tests to determine the extent of his injury, along with its potential short- and long-term effects. If this whole process isn't enough of a nail-biter, remember you're the one who decides whether or not he can get back on the field. Consider a few minutes of meditation time before you tackle that task.
Finally, remember that many sports physicians maintain private practices in addition to their team-related responsibilities. That means you're frequently juggling schedules to accommodate your own patients and make some time for your family and friends. Perhaps you need a stress management course. Wait, there's no time to take one. Maybe you can download a prepackaged class, and listen to it while you're sprinting back and forth across town...or across the country….