In October 2016 I was in hospital. I had been ill for 11 years with something I called chronic fatigue syndrome, but in the previous six weeks I had been overtaken by a strange, sudden crisis. I was unable to eat – a day when I managed a couple of biscuits was a good day; at times I trembled so violently that my voice shook; at night I was overwhelmed by dread.

In the hospital ward a consultant gastroenterologist appeared.

“How do you feel?” he asked.

“I feel,” I said, “very ill.”

This, apparently, was not the concise yet comprehensive answer that I had imagined it to be. He seemed to require something more. “Can you describe it?” he asked.

I couldn’t. That anguished, pressurised feeling – a sensation somewhere between burning and falling – that extended through my torso, my limbs, my entire body was by now so familiar to me, I was astonished that it didn’t have a name and that I didn’t know it. How could this be? I was, after all, a prize-winning novelist.

Frustrated I fell back on anger. Was the doctor stupid? Didn’t he know what “feeling very ill” meant?

In her essay On Being Ill, Virginia Woolf says, “let a sufferer try to describe a pain in his head to a doctor and language at once runs dry”.

At least I was in good company.

I remember very well what I wanted to say to the doctor: “I feel like I am about to fall off the world.” I had the sense to realise that he would probably not be able to do much with this. What doctors need is a clear description of something physical, but what the sufferer experiences may be as much emotional as it is physical – it may even have a spiritual component. It is very difficult in my experience to separate the different strands.

Nowadays, in the pit of my stomach there is a feeling I call anxiety. But when I ask myself what this sensation actually is, I realise that it consists of almost nothing at all – a very slight pressure. Yet, in spite of its nigh-on non-existence, the emotional weight of it drags at my days, pulls them all askew and makes me feel, despite my best efforts, constantly on edge.

Woolf says, “All day, all night the body intervenes …” And that is true: all day, all night the body is talking to us; but not necessarily in a language we understand.

Illness brings us up against the limitation of words, reminds us that what we experience will always be greater than the words we have to describe it. Dreams, silent meditations, experiences of God, moments of transcendence, moments we are aware of love, all of these evaporate into thin air, unless we scribble them down. At the age of 30, Julian of Norwich had an illness. Believing she was dying, she experienced a series of visions of God. The visions lasted for only one night, but she spent the rest of her life trying to distil them into a form that could be understood by other people. (She wrote two different versions, to be on the safe side.)

There is hardly any sense of struggle in On Being Ill. Struggle is what the healthy are doing, beyond the invalid’s window pane. Ant-like, they are rushing to and fro, being clerks and bus conductors and widows and lawyers. The shadowy figure at the essay’s centre – the figure who might be Woolf or who might be us – seems almost delighted to have fallen ill. They float like a stick on a stream; they are as gratefully irrelevant as a dead leaf being blown across a lawn; they watch the clouds mutate and form pictures above a London entirely unconscious of the beauty above its head.

This was an insight that I too gained in illness, and it is part of what I tried to write about in Piranesi: that there is a whole world endlessly going on, endlessly being beautiful, regardless of whether anyone is there to see it or not. Where Woolf and I part company is in what this means. For her it was evidence of the stark indifference of the universe to human beings: “Divinely beautiful it is also divinely heartless.”

For Piranesi, the central character of the book, and for me, the sheer profligate abundance of beauty is evidence of a universe intensely bound up with its creations. Piranesi walks through his world, cataloguing its contents, describing its wonders. This he considers his chief task in life. “The Beauty of the House is immeasurable; its Kindness infinite.”

But perhaps the greatest joy of Woolf’s happy invalid is a sort of intellectual freedom. Cut off from the life of the busy bank-clerks and the bus conductors, widows and lawyers, they are free to read Shakespeare in a new and thrilling way, a way not available to them when they were healthy. Finally they are free from the shackles of other people’s opinions; they no longer care what anyone else has said about Shakespeare; they can read him and have their own thoughts.

As an ill person, you have gone down into a sort of underworld, sometimes oppressive, sometimes not; either way, what people say and think in the world above matters less and less. This can be very freeing for a scholar, a saint, a musician or an artist. I remember Kathy Acker saying something similar when talking about her writing process. At least I think it was Kathy Acker; I’m going back to the 1970s, so I can’t be entirely sure. But whoever it was described a nocturnal existence; she wrote at night in order to be free from other people’s thoughts.

To return to illness and language. If, in one sense, language “runs dry” in the face of illness, in another sense it is desperately needed. I remember in a discussion group long, long ago (I think about the importance of story) a young woman saying that she had once been ill and that she couldn’t get better until she was able to tell herself a story about what had happened to her. This struck me at the time as an important truth.

To take the simplest of examples: an elderly woman I knew used to suffer from neck aches. Whenever this happened, she would tell herself the same story: “I have this pain because I was silly and I sat in a draught from an open window.” She might have been aware of the draught at the time or she might not. It didn’t really matter; the existence of the draught could always be deduced from the existence of the pain, and as long as she was vigilant against draughts in the future, the pain wouldn’t be able to return.

A narrative makes illness seem rational – and it gives the sufferer a measure of control – or at any rate the illusion of it. This is particularly true of the sort of chronic illness in the face of which poor doctors are often at a loss. There is no obvious course of treatment for fibromyalgia, chronic fatigue, chronic pain, long Covid and all the myriad forms of chronic illness. There is no drug to take that will restore you to who you once were. There is only narrative.

I know very well how grateful you feel to the doctor or therapist who provides a narrative to explain what has happened. And how upset and angry you feel when a different, perfectly well-meaning, doctor says something else or offers a theory that seems to threaten that narrative.

Of course one of the problems with being a writer with a long illness is that one can produce narratives without number. What would you like?

I can do you a revengeful, blame-apportioning narrative.

“She became ill after months of book tours, during which she crossed and recrossed the Atlantic on numerous occasions, all the result of her wicked publishers spending large sums of money on promoting her first novel – presumably out of sheer vindictiveness.” (A journalist once spent a surprising amount of time and energy trying to get me to say this.)

I can do you a zoological narrative.

“She was bitten by a blood-feeding tick and caught Lyme disease.”

I can do you a fairytale narrative.

“She wrote about fairies and now they have exacted their revenge and she lies ill of something mysterious and Lady-of-Shallot-adjacent.”

I can do you a childhood-adversity narrative.

“She was told as a child that she would never succeed and indeed did not deserve success. Having achieved success, she promptly fell ill in order to comply with her upbringing.”

I pause here. The narrative of being told I did not deserve success pulls at my heart, not only for myself, but for others too. Because, of course, I wasn’t the only girl of my generation to be told that. My school – a comprehensive on a run-down Bradford council estate – produced, as far as I know, only one other writer, Andrea Dunbar, a playwright of extraordinary talent. I don’t think I ever met her, but she must have been a year or two below me. She died at the age of 29 of a brain haemorrhage, possibly related to alcoholism. My best friend during the same period was a ridiculously talented musician who went on to have a hit record. She died before the age of 40.

You see, from one point of view, I got off lightly.

But if illness can be a story, so perhaps can the cure.

There is a bunch of interrelated therapies, all fairly recent, that share an interest in narrative. They are pain reprocessing, somatic tracking, polyvagal theory and others. The underlying idea is that in some people – and I stress some people – chronic illness might look like this: a very ancient and primitive part of the brain and nervous system believes it has detected danger, possibly a tiger or something like that, and so it produces pain or a whole range of symptoms in an effort to get the sufferer to close down and protect herself. The nervous system does this very effectively and it can carry on doing it for decades. It is really very inventive. I feel that mine ought to be eligible for some sort of prize.

It comes to this. A story you have on some level believed – that the world is fraught with danger – can be countered by a different story. Yes, the world is fraught with danger, but not everywhere, and not always, not here in this place and not now in this moment. You are safe.

So this is my narrative now, the story of how I got ill – and perhaps, if I pay careful attention to it, I will be able to retrace my steps through the labyrinth of my own body and return to safety.

• This essay was originally commissioned for Charleston festival.