I became a primary teacher after banking, civil service, management consulting and being a sales & marketing director of a big international company. There'd been pressure, all night working, lots of travel etc in all but the first.
What's different about teaching is that it is responsibility without power, combined with a high proportion of non-discretionary time. Bodily functions do get contorted to the school day. You can't take five minutes to book an appointment as your breaks are completely consumed by dealing with children, photocopier wrangling, being on duty or running a club. This is not just 8:45-3, but factor in compulsory staff and team meetings and extra curricular and these are long days being effectively pinned to a place. And I know that is true for many many other jobs: the difference is that while you're pinned there, you are acutely aware of the other work that is being generated... the marking, the need to change planning, the need to completely rethink the way you were going to do something because your headteacher has a new vision, the need to make extra resources to support all of these changes. Factor in the negligible amount of time you get for meaningful discussion with fellow professionals (some schools simply can't timetable teachers to be out of class together) and it can be very lonely.
I don't think there is a personality type in teaching, but I do think that many people with the potential to be really brilliant teachers experience huge stress because they are all too aware of where they are not being as effective as they could because of the pressures and/or the pointless initiatives and paperwork. They either burn out trying to be fabulous in spite of all the crap, or they become disillusioned and overly self-critical.
And in how many other professions can a career be ended by the subjective judgement of someone watching them work for 20 minutes. That sounds dramatic, but an underconfident headteacher, charged with taking action after a poor Ofsted, will more often than not prove their 'relentless drive to raise standards' by hounding the perceived weakest link until they leave. There is no real way to challenge observation feedback and results at primary level are so nebulous there is little to draw on objectively to defend oneself.
So, not more stressful than air traffic control, or bring a paramedic, or taking a penalty at the World Cup. But underneath the iceberg of the visible parts of the job, for five days a week, seven or eight weeks in a row, it is pretty crushing. Fantastic highs to compensate, but sometimes not enough.