I just wrote a really long post answering this question. Apparently it got lost when I posted it, more or less at the exact same time that corpsman posted his. So I'm going to blame him!
The health risk is real, age-adjusted cardiac risk is x2 the first decade and x3 the second. Everybody has quit or died by the third. This was a factory shift work study as Corpsman has suggested. Note that it was a retrospective cohort adjusted for cardiac risk factors. It was rolling forward one week shifts. This is really bad for your circadian rhythm. You'll learn all about this in residency.
. Best advice: work only one night shift at a time (so you don't reset your clock). Failing that work no less than 3 weeks at a time so you completely switch over. Do not become the prince/queen of darkness and work only nights. It makes your partners very happy, but it messes up your family relationships, your professional growth and you become chronically sleep deprived (getting about 5.5hrs/day.) The other health suggestions that corpsman makes are undoubtedly helpful.
I tell my graduates that each of them has number of patients, specific to them, that they can see in a career. They can front load them at a high acuity/volume place to make money quickly. If so they will be cutting back pretty soon. Or they can choose a low or medium volume place and work at that rate for a long time.
The administration/teaching thing is helpful, but I can tell you it has it's own high stress. Also, it's not open to everybody.
As for your question abut holding up for a career, I've been doing EM since I entered residency 28 yrs ago. I work 9-12 8.5 hrs monthly with 1-2 nights. I do about 100-120 hrs of admin/teaching/research monthly. It works out to 50-60 hours. I worked the same # of hours when I was younger, with more of it clinical. I'm 55, still in good health and can't imagine retiring. I rarely get excited in resuscitations and my pulse never races anymore. I don't raise my voice when the team hasn't got it together. I still learn something new everyday, and it's been a bad day if it was only one thing. That's good news for you, you'll never have a reason to be bored. I could see a career adjustment in a few years to the medical student teaching end.
By comparison, Debby and I went to our 35th high school class reunion 2 years ago. A much higher proportion of our class had retired than of my contemporaries in our specialty.
About life expectancy, when I was a freshman medical student (1972) I used to read the obits in JAMA. It was amazing, it seemed to me that almost all of the docs listed there died in their 50s. They had been on call solo their entire professional life, being the GPs or Surgeons for an entire community. Today, with adjustments to night call/continuous call, group practice etc, Docs live normal lifespans.
If you overwork (whatever that is for you personally), you'll get exhausted, depressed and burn-out. I think if you follow the rules about circadian rhythm and you don't overwork, you'll have a good life and a good career.
Cheers, bkn
now let's just hope this thing posts.