I once knew a man, a Jamaican, who when he first came to England always answered truthfully when asked ‘How are you?’ A bit sniffly, he might reply; or he would describe his indigestion, or the twinge in his left knee. One day a woman lost patience: ‘Look,’ she snapped, ‘there’s something you must understand; in England, the answer to “How are you?” is “I’m fine, how are you?”’ So he’d been told, and he didn’t need telling twice: for all the English care, you can die and stiffen on the street.

There is another culture gap, less easy to bridge, between those for whom illness is a rare and indisputable fact – they have, for example, broken a leg – and those for whom the signs of ill-health are just the beginning of a series of complex negotiations with the body and the outside world. For some of us, the question ‘Am I ill or well?’ is not at all straightforward, but contentious and guilt-ridden. I feel ill, but have I any right to the feeling? I feel ill, but has my feeling any organic basis? I feel ill, but who am I to say so? Someone else must decide (my doctor, my mother) whether the illness is real by other people’s standards, or only by mine. Is it a respectable illness? Does it stand up to scientific scrutiny? Or is it just one of my body’s weasel stratagems, to get attention, to get a rest, to avoid doing something it doesn’t want to do? Some of us perceive our body as fundamentally dishonest, and illness as a scam it has thought up. When a hypochondriac asks ‘How are you?’ he really wants to know, and he wants to know what you think about how you are; his problem is that, before the conversation is over, he may well have developed your symptoms himself. Hypochondria is not – or not only – a form of self-indulgence. It is also a form of pathological empathy. Charles Darwin wanted to be a doctor, but was too sensitive to human suffering. It is a worrying thought – worrying enough to raise the pulse rate – that nurses and doctors are an elite, self-selected as sufficiently insensitive to get on with the job.

For the Greeks, the hypochondrium was the area just below the ribcage, the site of digestive disorder. This region of the body is where feelings of unease pool, then overflow. It is dangerously proximate to the heart; by the 16th century, the gnawing, mobile, ambiguous pain was associated with melancholia. It afflicted all parts of the organism, and yet no particular part. In engravings, its languishing victims, head resting on palm, surrounded themselves with the pots and jars of the apothecary, but he could do little to cure their gripings, rumblings, belchings, vertigo and bad dreams; nor could he cure the accompanying emotions of anxiety and grief. But which came first, the physical or mental symptoms? Could they be divided? Was the disturbance on the bodily plane, or the astral plane? The melancholy man might fall into the delusion that his body was altered in some fundamental way; there was a frog or serpent inside him. In 1685 Thomas Willis judged the melancholic-hypochondriac patient to be prey to ‘wandering pains, also cramps and numbness with a sense of formication’, as well as low spirits, wandering attention and fear of death. Since then the term ‘hypochondria’ has withered in meaning. For Freud it was merely ‘the state of being in love with one’s own illness’. But it seems to be more complicated than that. There are diseases that are artefacts of treatment, produced by doctors; there are diseases that are produced by thinking about doctors. In hypochondria, the whole imagination is medicalised; on the one hand, the state is sordid and comic, on the other hand, perfectly comprehensible. It is the dismaying opaqueness of human flesh that drives us to anxiety and despair. What in God’s name is going on in there? Why are our bodies not made with hinged flaps or transparent panels, so that we can have a look? Why must we exist in perpetual uncertainty (only ended by death) as to whether we are well or ill? John Donne speaks of illness as an invader, which sets up a kingdom and conceals ‘secrets of State, by which it will proceed, and not be bound to declare them’.

So profound are the effects of the belief that we are ill that hypochondria must be seen as a pathology in its own right. The imagination’s ability to affect the body seems limitless; at least, no one has fixed its limits yet. It is difficult to draw a line between health and illness in a system that is never in stasis and can never be viewed objectively; findings at autopsy are no guide to the lived experience. The hypochondriac is not a healthy person with a delusion, so much as a person who is pre-ill; the anticipation creates the very condition he fears. A pattern of suspicion becomes a way of life. Adopting for a moment the familiar, modern and derogatory meaning of the word, Brian Dillon consoles us that ‘hypochondriacs are almost always other people.’ The condition exists on a continuum, with fraud at one end, delusion in the middle and medical incompetence at the other end; he is a benefits cheat, you are a hypochondriac, I am as yet undiagnosed. Some of us, mostly men, regard their bodies as machines, and service them when they begin to grate and creak, or when they sputter to a halt by the roadside. Some treat their bodies like lovers, to be flattered and indulged, second-guessed and placated in the hope that they will thrive. All of us treat them as other; they are not our essential selves, they are what we drag around with us, a suitcase or steamer trunk with dubious, ever shifting contents, a piece of luggage we didn’t pack ourselves. Many people are simply hyper-aware of bodily sensations, and so are driven continually to check in with themselves, examining visceral events as a man about to confess to a priest examines his conscience; like the believer scrutinising himself for sin, they expect to find something bad, perhaps something mortal. Forgiveness, and cure, are only ever partial and temporary; there will always be another lapse, some internal quaking or queasiness, some torsion or stricture, some lightness in the head or hammering of the pulse, some stiffness in the joint or trembling of the limb, or perhaps even an absence of sensation, a numbness, a deficit, a failure of the appetite. A state of abounding good health can in itself be a cause for suspicion. Just as the sufferer from bipolar disorder knows that present cheeriness will lead by and by to breaking windows and gambling away one’s shirt, so the migraineur knows that a jaunty sense of well-being is likely to be the precursor to a splitting headache.

Brian Dillon himself lived for many years, after the early death of his parents, with anxiety about his own health. His nine case studies embrace writers and artists, thinkers and iconoclasts; they are full of insight and beautifully constructed, with a wealth of cultural reference and a breadth of imagination behind them. Are artists and intellectuals more sick and/or hypochondriacal than average, or are they just more likely to report in detail on their worries? It is reasonable to think that those who are highly sensitive to the outer world, and who constantly interpret it, would be sensitive to the inner world too, and would seek to ascribe meaning to the body’s negotiations with itself. Some of the case studies are familiar: the asthmatic Proust in his cork-lined room, protecting his privacy and his senses from the chestnut trees on the boulevard Haussmann, the bustle of the shoppers at Printemps and the travellers at Saint-Lazare. ‘My duty is to write my book, do my work,’ he said. ‘I haven’t the time for anything else.’ For him, illness was an enabler, the sickroom a stage which he arranged. Dillon offers us Walter Benjamin’s image of the writer’s bed as ‘the summit of a scaffold on which Proust lay flat, holding his manuscript above him, his face pressed against the upper reaches of his imagination’. Proust’s father, a doctor, was a fresh-air fiend; there is probably another book to be written about how the sick and quasi-sick relate to their parents, how they react against them or conciliate them, and on the clumsily named but horribly real Münchausen’s Syndrome by Proxy, in which parents, for a variety of motives and in a variety of ways, make their children ill.

In Dillon’s essay on Proust we see how diseases can change class: in the 18th century, asthma was an artisan’s affliction, but by the 19th century it was thought of as a disease of the leisured. Hay fever, which seems plebeian nowadays, was also a high-class condition. Once you rise above cold nights and earth floors, the diseases of affluence are waiting for you, and probably a good many well-off allergy sufferers were responding not only to pollens, but to house dust mites breeding in comfort in their carpets, curtains and bedding. Hypochondria itself was a product of luxurious living, according to George Cheyne, a physician and pioneer of vegetarianism, who in 1733 published a book called The English Malady. Cheyne’s thinking is familiar to us: live plainly and keep busy, and you won’t have time to worry about your health. This prescription is too simple, because those with health anxieties are among the busiest people on earth. The young Boswell, travelling in Holland, was prey to all sorts of debilitating symptoms: ‘Oh dear! I am very ill.’ A friend advises keeping a journal and ‘debauching a Dutch girl’. The journal meant as a solution then becomes Boswell’s problem; he is compelled to try to record everything he thinks, does and plans, but he is always behind with the record, which makes him feel guilty and useless. He cannot keep himself from devising demanding courses of study, at which he is bound to fail; he has difficulty in getting out of bed in the morning, difficulty in starting writing. Do procrastination and hypochondria often go together? Is hypochondria a creative mechanism employed by the perfectionist? Each crisis of illness is succeeded by a fresh start, which is what the perfectionist craves above all else. The body is purged, light; the page is blank.

Boswell in Holland was afflicted by homesickness, that poisonous form of nostalgia which can throw up all sorts of physical symptoms. So was Charlotte Brontë, in Brussels to perfect her language skills. Her novels, Dillon points out, are full of hypochondriacs: Lucy Snowe in Villette, for example, is subject to ‘an overheated and discursive imagination’. In Brontë’s work the boundaries of the term are explored; the ‘hypochondria’ from which Jane Eyre suffers on the eve of her wedding is a crawling (and well-founded) apprehension that disaster is around the corner. Our bodies make us know things our mind doesn’t quite know, or won’t accept: ambiguities in our situation, undeclared and forbidden loves and hatreds. How painful it would have been for Florence Nightingale’s family to face their mutual feints and deceptions; how much easier for one of them to develop a symptom, which would then magnetise attention. The members of sick families pity each other; this pity often disguises mutual jealousy. Florence Nightingale described her life as ‘desperate guerrilla warfare’. From Lytton Strachey onwards, her biographers have seen how she turned ill-health to her advantage. For Victorian women who were sheltered and disempowered, illness was something to do, a pastime; but it also allowed secret and purposive activity. Nightingale conducted strenuous and effective public campaigns from the citadel of her sickbed. Some men also needed this protection. Darwin wrote that ‘ill-health, though it has annihilated several years of my life, has saved me from the distractions of society and amusement.’

Attempts at posthumous diagnoses of Darwin’s illness – was it a tropical disease, arsenic poisoning? – are interesting but, for Dillon’s purposes, beside the point. The body organises what the soul needs: seclusion, privacy, an exemption from the chore of getting dressed for dinner and making small talk, an excuse for reading rather than dancing. It doesn’t matter much whether Darwin or any of those Dillon writes about was ‘really’ ill. The fact is that they were suffering, and often in some productive way; though the saddest and bravest of Dillon’s subjects was the least productive in the world’s terms, someone whose art simply produced herself: Alice James, sister of Henry and William, Alice with her ‘squalid indigestions’, her ‘spinal neurosis’ and her ‘stomachic gout’. Between them the James siblings shared a hospital full of symptoms, but Alice was the champion when it came to baffling doctors. When after decades of ill-health she was told she had a tumour, and would die, she reacted with a sort of relief, even exaltation. She was at last being told what she had long suspected – there was simply nothing to be done. ‘Ever since I have been ill, I have longed and longed for some palpable disease, no matter how conventionally dreadful a label it might have.’ What she wanted was some objective confirmation of the subjective malaise that had dogged her for years. Modern patients will understand her plight. Diagnostic tools improve all the time, but before they can be applied some authority figure must accept for the sake of argument the existence of an illness, and hazard a guess at which bodily sub-system might be affected. The undiagnosed are like stateless persons, ejected from the office of one consultant, washed up at the doors of another specialty, booted out of a third clinic with question marks all over their notes; sometimes it is a relief, however hellish the final destination, to be granted leave to remain.

Daniel Paul Schreber is the least known of Dillon’s subjects, and we may fairly regard him as the one plunged deepest into the pit of hypochondriac delusion, since it was definitely not true that 240 Benedictine monks were living in his skull. Freud wrote him up in 1911, but his own account was given a few years earlier in Memoirs of My Nervous Illness. Born in Leipzig in 1842, Schreber became an eminent jurist and a heroic sufferer. He was subject, he felt, to assaults on his body which he called ‘miracles’, though they were of a malign type. Dillon describes an array of ‘extraordinary amputations, evacuations and disappearances from within the unguarded precincts of his body’. He was bombarded by rays. Sometimes his stomach vanished and his food went straight down to his legs. He had survived so much he feared he might be immortal. He was also turning into a woman, who would be impregnated by God and found a new race (he was the sole survivor of the old one, since all the people walking about in the world were dead already). From time to time Schreber was able to corral his delusions and live among the well. But after five years during which his symptoms remitted he became subject to the appalling conviction that his body was dead and rotting, while his head was still alive.

Freud located Schreber’s illness in his denial that he was sexually attracted to the asylum director who was the arbiter of his fate. Perhaps Schreber was frightened of his doctor, and fantasised about sex as a means to placate him? Many patients, Alice James among them, sense from time to time a strong wave of hostility from their carers. Alice felt, Dillon says, ‘exposed, degraded and reduced by the medical gaze’. The hostility of doctors and nurses to patients (who provoke in them fear and sensations of powerlessness) is one of the great taboo subjects, but it is no secret to the assiduous and dedicated patient. A doctor wields immense power; his cures can kill more efficiently than the disease itself; he can also deal out existential death. Andy Warhol was particularly suspicious of doctors, who he believed had given his mother an unnecessary colostomy, thus creating a shameful confusion between the outer and inner worlds, between what can be looked at and what ought to be concealed.

Many artists and many hypochondriacs seem to have one skin too few; boundaries are continually violated, the world impinges. The pianist Glenn Gould, at one stage in his life, took his blood pressure hourly; he tried to turn down the sensory excitements of the outside world, wearing grey and brown and eating arrowroot biscuits, reducing input to a minimum and aiming to live like his own ghost. Patted on the shoulder by an employee at Steinway, he felt the pat to be a blow, an assault which had ‘compressed or inflamed or whatever’ the nerves of his hand; he cancelled a European tour and filed a lawsuit. What Dillon calls the ‘strange combination of intensity and ignorance’ with which he approached his body was characteristic of Warhol too. He went in for crystal healing: ‘It cost $75 and he told me my pancreas was the only thing still giving me pimples.’ Warhol cultivated his own ‘chic freakiness’, at one stage avoided people suffering from what he called ‘gay cancer’ and treated phantom ailments but not his real disease, refusing to have an infected gall bladder removed. The operation eventually took place, and was a success – except that he died after it. Heart failure was the proximate cause; we cannot say for sure, Dillon notes, that he died of fear, but a persuasive case could be made. In hospital, Warhol noted, ‘they tell you something, and you don’t know what’s going on, they’re the ones who know, you’re at their mercy … ’

His position is unreasonable, but sick people, or those who believe they are sick, are not reasonable creatures. Like animals, they are sensitive to the invisible, aware of all the undercurrents of their situation, but often in too much distress to articulate them. And yet, it is their own distress; it is self-generated and self-selected, not imposed by society; pain is private, when so much else is not. Perhaps only very simple people are not hypochondriacs at one time or another. For the intelligent and inquiring, a measure of hypochondria may be a necessary self-soothing. Anxiety about a specific symptom is more bearable and easier to rationalise than the diffuse ontological malaise that used to be known as spiritual despair. It is easier to say ‘my knee is killing me,’ because we know it isn’t, than to dwell in the belief that the clock is ticking and that the journey from birth to death is a journey to extinction; it is better to have a symptom than to have a void inside. We dimly sense that, like Alice James, the task of each of us is to ‘get myself dead’. But until we reach what Alice called ‘the vanishing point’ our symptoms lull us with all sorts of stories about our still living selves; our pain teaches us that we are alive, and our symptoms are the body’s speech, riddling and allegorical, full of overblown conceits and mixed metaphors. Ignore the message, and another will be produced, more brutal this time, to rot the liver or stop the heart.

But there is no need to shrink from what Alice, again, calls ‘mortuary inclinations’. These are great days for the worried well. Open any newspaper and you will find an outbreak of contrary, confusing, half-nonsensical stories that feed health anxiety. The internet is the tool par excellence for those with a twitch or a wart or a chill, and the democratisation of the medical lexicon has caused acute anxiety to doctors, facing them with a doleful loss of status. A few years ago it was routine for them to snarl at patients: ‘I suppose you’ve been looking it up on the internet.’ Now what is more usual is a swallowed and hasty explanation, broken off with a resigned flap of the hand: ‘Well, you can look it up, you will do anyway.’ In the days before internet information and misinformation became available, patients often came away from a consultation with the feeling that they did not own their own bodies, that they were in some way owned by the doctor or the NHS. Now perhaps Google owns our bodies; it is possible to have access, at a keystroke, to a dazing plurality of opinion. There is an illness out there for every need, a disease to fit any symptom. And it is not just individuals who manufacture disease. As drug patents expire, the pharmacological companies invent new illnesses, such as social anxiety disorder, for which an otherwise obsolete formulation can be prescribed. For this ruse to work, the patient must accept a description of himself as sick, not just odd; so shyness, for example, becomes a pathology, not just an inconvenient character trait. We need not be in pain, or produce florid symptoms, to benefit from the new, enveloping, knowledge-based hypochondria. We are all subtly wrong in some way, most of the time: ill at ease in the world. We can stand a bit of readjustment, physical or mental, a bit of fine-tuning. Our lifelong itch for self-improvement can be scratched by a cosmetic surgeon with his scalpel or needle, our feelings of loss assuaged by a pill that will return us to a state of self-possession. For hypochondria, the future is golden.