I completed my PhD with both a very visible "disability" and a long term chronic illness.
The disability didn't really impact on my work but, surprisingly was horrifyingly badly accommodated by the university (I have written another entire blog post on the subject!).
My illness on the other hand had a very big impact on how I worked, but luckily I was very well supported by the university.
Adapting to Chronic Illness
The single most important thing was that I had a very good relationship with my supervisor and I made sure that he had a good understanding of my illness. This did mean revealing diagnoses etc. Not everyone would be comfortable doing this, but this was a choice I made and it worked well for me and the supervisor I had.
We had gone over in detail what I could and couldn't do. He knew in advance that I would NOT be doing a normal working week and that there would be periods of time when I wouldn't do any research.
One thing I soon found is that there is no such thing as "normal" if you are sick. I needed to forget about what everyone else was doing and concentrate on what worked for me. It really didn't matter if I did things completely differently to everyone else. Different is never bad per se as long as I get where I need to. Luckily I had the full support of my supervisor in this regard.
Split Office + Home Working:
When I was "well" or "as good as it gets", I still couldn't work all day. I always felt at my worse in the afternoon and it soon became clear that working at that time was simply inefficient. Since I was definitely going to have to have time off and there is no official scope for that in a PhD (there is no equivalent to sick leave), I needed to make every single hour count. So I always worked when I felt at my best, regardless of what time it was. Conversely I didn't make myself work when I felt absolutely awful. The quality of the work was generally poor and I just made myself feel sick for longer.
So I started only going into work in the morning and coming home and resting or even sleeping in the afternoons. I would then maybe do a few hours late evening (eg 10pm-1am).
On the other hand I was often up at 3am in pain or with other symptoms. I soon found that that time could be put to surprisingly good use. I took to jotting down ideas and/or reading "easy" research papers.
As time went on and my illness deteriorated I would alternate days I went to the office. For instance I might go in Mon, Wed, Fri and work fully from home Tues, Thurs.
I asked that most PhD seminars and teaching get timetabled in morning slots. This was mostly done and was of great help to me throughout my time as a PhD student. The location of said seminars was not always so well looked after, but I was very impressed with the way the university accommodated this particular requirement.
Conferences or talks at other universities were extremely difficult for me and I had to rest for long periods after. I worked from home for days after any such event. I went to less conferences and events than my fellow PhD students and as such these were carefully selected to maximise their use and impact.
Housebound: (12 months on and off)
Roughly 12 months of my PhD were spent this way on and off. These housebound patches were unpredictable. I might be housebound for a week here, a couple of months there and so on and so forth.
The biggest problem here was probably not academic but emotional, mental and social. The lack of contact at the office is obviously very isolating. Throughout my PhD I would always try to go into the office when I could, not really because I needed to for work, but because it was good for me mentally.
Luckily I pretty much lived on campus and was able to get a social life going by inviting people to my flat. This became a regular event with people coming round for lunch and evenings several times a week. This really helped prevent me becoming lonely and disconnected from university life.
Hospital and/or Horribly Sick! (8 months on and off)
This might not have been so bad had it been under my control. The thing is that it happened at unpredictable times: a few weeks there, a month here, a few days there and this was extremely disruptive.
At least 4 months were spent in hospital/recovering and so ill that even background reading was impossible.
I was "lucky" enough to get a very good result (proof of a new mathematical theorem) quite early on in my PhD which meant that my success was pretty much assured from 20 months in. Therefore because things were going so well, my supervisor was happy to let me just rest until I felt well enough to start working again.
Thus I was not required to take a leave of absence, avoiding the bureaucratic and financial difficulties that many sick and disabled PhD students face at precisely the time that they are at their lowest.
I am of course very aware that I was extremely fortunate in that regard and that not everyone would be able to do this.
Success thanks to flexibility but at a cost
However I recognise that spending an enforced 8 months doing background reading or even nothing at all, yet still finishing on time will not be possible for everyone. The subject I was doing helped a lot (no lab work + an early "result") and I think this was the deciding factor. I think I would have struggled far more in other subjects, however good I was at them and would have needed time off, with all the financial and administrative issues that entails.
Ideally there would be provision in the system for someone like me who is ill: ability to go part time, extra funding, etc. I would certainly have welcomed it and felt under less pressure. But there isn't. At most you can defer, but are left without funding or support.
Despite the fact that my PhD couldn't have been going any better, I continually felt very much that I was in a "sink or swim" position, and under tremendous pressure to "be well". Ironically this was likely to be counterproductive and make the illness worse. In the later stages of my PhD I had to keep reminding myself that things were going very well and I did have some leeway if I got sicker.
Additionally I was always playing "catch up". I would be on target and then have a period of bad health and feel that I was behind again. My trick in the end was to try always to be slightly ahead if possible, (as long as I didn't make myself sick in doing so).
This came at a big cost. Although I did have time for a few social evenings as long as they took place at my own flat, most of the time every "useful" waking hour was spent working. The rest of the time I was resting or simply really sick. So although I was successful in the end, it was at great expense, sacrificing nearly all of my leisure time. I imagine this is something a lot of my fellow chronically ill PhD students can identify with.
I think these mental, emotional and physical burdens for sick PhD students cannot be emphasised enough. It is a huge addition to an already difficult task.
After my PhD, when I got my funding for my first research fellowship I did, in fact, go 75% part time. This finally took some of the pressure off at the times when I was very ill and unable to work at all. I also had some time to enjoy a more balanced lifestyle. Emotionally and mentally things became much easier.
If more people with chronic illnesses are to succeed then more part time work and study and the ability to flexibly slip between them should become available. This IS possible and the best example I know of is the one offered in the Dorothy Hodgkin Fellowships. I would love to see more research councils and universities offer similar schemes in the future.