MA to PhD

A PhD is much more stressful than an MA, so far as I know.  IMO we are really left to the wolves here in the UK as compared to the US - but it's seen as a test of your ability to be an academic professional.

People are usually OK with one or two "explanations" and then you will just start to look like you can't cut it, regardless of your actual situation.  Academia is often cut-throat and you need to manage your image if you want to be taken seriously in the future.   

I would them your situation as matter-of-factly as possible, tell them your plan of action (I will have X done on Y date, etc) and then follow through. 

and yes, you need to manage your stress by turning in your best possible work based on what you've been through.

Maybe see if you can take a week or two to polish and then move on.  But your next submissions should be as stellar as possible to dispel any doubts.

Making yourself sick again isn't going to help you accomplish anything.

My experience so far has been really enjoyable.  My primary supervisor has requested we meet once per week to discuss readings (which I typically send him my thoughts in advance).  In addition, we meet informally for coffee at least once per week with a few others in the department (its more like a revolving door of people and discussion topics).  My main seminar meets fortnightly, but there are other seminars/centres which meet as well and I sometimes attend those as well.
Compared to my work in the US, I feel more comfortable here in the UK.  We are required to fly solo a lot earlier than US programs, but it's not the same kind of flying solo (I have "horror stories" of some professors in the US).  It helps if you have a clear-cut research goal, especially you have had some lower-than-expected marks in courses that are unrelated to that (I had low marks in one of the 5 religious traditions which was required for my MA).  Also, do work with an achievable goal.  You'll have 3 years of actual time (part-timers just get this spread out over a longer period of time).  Some programmes (like my friend's down in Bristol) want writing right away (he had to turn in 5,000 words by the end of his third month); but others (like mine in Glasgow) is more relaxed (my supervisor doesn't want anything until the end of this year, followed by a good draft at the end of the second year).

I found my Ph.D. less stressful than my undergrad thanks to not having exams, essays and such. I didn't have to take classes and just got to do science all day. Even the thesis wasn't even that bad.

I assume both Masters and PhDs still require a defense.  It's not the every day part that is hard, it's what you have to do to get done with it.

PhD's need to be much more familiar with everything about their subject than Masters - and if you get someone on your committee who wants to bust your balls, it's going to be much worse at the PhD level.

Taught masters don't usually have a viva. Research degrees do tend to, and Ph.D.s definitely do. A good supervisor will give you good examiners who won't be mean for the sake of it. I was quite nervous going into it, but I actually rather enjoyed my viva- it lasted for about 4.5 hours (longer than normal for science) because we were having such an interesting discussion! The viva is not meant to trip you up, it's meant to verify that you've done the work and understand the subject; if you have, you won't have a problem!

This is exactly what a viva/defence is supposed to be:

The viva is not meant to trip you up, it's meant to verify that you've done the work and understand the subject; if you have, you won't have a problem!

Typically, you know well in advance who will be on your committee and, if lucky, even have initial feedback from them before the viva.  It's the student's job to get a "good" supervisor who then should (1) prepare the student for the job of a professor (which is primarily research, publication, and instruction) and (2) see to it that student succeeds.
Also, I think I may disagree with hollyberry in that PhDs need to be "world-leading experts" in their research area, but that's the extent to which their familiarity with the general subject differs from the Masters level.  This is why a lot of PhD programmes in the US do not require a separate Masters and even gives one "along the way" if a students desires.  The Masters student (at least in the humanities) is expected to have a strong understanding of the key concepts and history of their field.  A PhD's research is expected to be very narrow and exhaustive in that narrow area.  There are times that I believe I have as much understanding in some course materials as the person doing the instruction for it when that person has not done a PhD (one example right now is Hinduism where my department does not have a professor who specializes in Hinduism, but there is one who did Japanese Buddhism and teaches from that angle).

When I got my MSc in the US (in a very small department), there was one prof who was on almost everybodies committee.  He was very acerbic and sarcastic (one of the things I liked about him), particularly with the PhD students.  Maybe it's 'old school' but a lot of PhD think its a right of passage to haze the students to test them on whether they are truly knowledgeable enough to cut.  Of course not every person in every place thinks that way, but I've seen it enough.

My major prof was very nice and gave me loads of support and guidance.  Other people weren't so lucky.  I came from a related but different program, so my knowledge was very much on a surface level.  I took a full load of classes each semester in addition to my research - so was getting a reinforced instruction of what I needed to know for my research (to a degree).

My major prof here is very nice but when one student (who was having personal issues) started clucking about the fact that we aren't getting much in the way of instruction - he quickly reminded us that we are Masters students and therefore expected to be self sufficient.  Once again, I'm in a position where I have to play catch up.  I didn't dive in head first, I'd have been left in the dust a long time ago.

and yes, you need to manage your stress by turning in your best possible work based on what you've been through.

Maybe see if you can take a week or two to polish and then move on.  But your next submissions should be as stellar as possible to dispel any doubts.

Making yourself sick again isn't going to help you accomplish anything.

Hmmm.. I "made" myself sick?

I plan to take no more than 2 weeks to finish these 10-pg essays. On the other hand, my profs (for my optional modules, not the main one) urged me not to worry about the essay, that my health was much more important. One of the classes, however, is a half-unit module that ended last term, so the essay is my whole grade. If my assessment is mediocre, my would-be research proposal is rather specific and doesn't involve this prof or her dept.

It was stress that compromised my immune system and made me vulnerable to pneumonia in the first place!  :\\\'(

So don't stress

So don't stress

Easier said than done!

I've been told by many PhD students that doing their MA was a thousand times more stressful than their PhD course (for similar reasons to superl99's).

I've been told by many PhD students that doing their MA was a thousand times more stressful than their PhD course (for similar reasons to superl99's).

Excellent! Glad to hear you've got it all sorted out 

My DH is submitting his PhD thesis (science) at the end of the month (touch wood!!). He already has confirmation of his external examiner and they have also agreed to have him defend within 4 weeks of submission as he has a post doc he needs to start by 1 April.

DH's supervisor is crap, though. So there's a bit of worry about that. The reality is that DH actually DOES know a lot more than his supervisor about the topic and the field in general. His supervisor is one of those academics who spreads themselves too thin and tries to be expert at too many things. So DH has clashed with him a few times over things.

FWIW, DH has also had at least 2 extensions on his PhD. Granted, they were for the birth of our kids, but he also had pneumonia and some other things going on as well. For the most part, the dept as a whole were very understanding.

My DH is submitting his PhD thesis (science) at the end of the month (touch wood!!). He already has confirmation of his external examiner and they have also agreed to have him defend within 4 weeks of submission as he has a post doc he needs to start by 1 April.

Congratulations to him!