I'm taking care of my first patient who might have TB. So before walking into her room, I put on a special mask, pass through an isolation room, and into her own negative pressure accommodations. It's funny how aware you become of the tiny variations in the contour of your face when you have to mold a mask tightly around them.
It sets people on edge, bringing starkly into relief how dangerous this job can be, even though TB is not the worst thing we deal with. And I think that's why medical humor becomes so morbid. I asked her nurse for the patient's chart, and she joked "only if you're not going to write any more labs on her. I swear I have TB already, running in and out of there like I do." That's probably not funny outside of this group of people, but we both laughed as if she were Eddie Izzard.
OK, maybe not that hard.
A better example was a few months back, while I was getting blood work done following a needlestick injury. I was pretty stressed, but attempted to shrub off the tension by telling the lab tech "I guess it's just an occupational hazard." He came back with "then I suggest you take up prostitution sir, the pay is better and there's no overhead."