I am the Head of a technical department (think mechanical engineers, software engineers, medical technologists, that sort of thing).
I have both hands-on delivery stress as well as people management accountability.
I work long hours, but like someone else up-thread said, most of my stress comes from some accountability which I feel I don't have enough control of.
In my case, the latest one is hiring people (such as grads) who just aren't up to the job, because that bit is led by HR (Personnel), with local managerial supporting the hiring decisions. Which means I get people who aren't my choice of hire, and yet I'm accountable from Day 1 (literally) for their output.
Does that sound stressful?
Yes! And it is!
On the other hand, there are lots of benefits, for one, I studied long and hard to get here, and get a lot of satisfaction out of the work. I'm also the only female at my level in the entire company. I'm rather proud of what I've achieved here so far.