Caroline Crampton was 17 and midway through her A-levels when she was diagnosed with Hodgkin’s lymphoma, a rare form of blood cancer. When the diagnosis was delivered in the consultant’s office, her mother fainted, quietly sliding off her chair and on to the floor. After months of gruelling treatment, Crampton was given the all-clear and went to university as planned. But in her first year, she found a lump on her neck that turned out to be a tumour. Crampton had further chemotherapy and a stem cell transplant, which was followed by weeks in an isolation ward and a period of close monitoring. At 22, she was declared cancer-free, and, five years later, had her last check-up. By then, she was told, she had no more chance of getting cancer than the rest of the population. What those check-ups didn’t address was the anxiety that had embedded itself in her psyche and has tormented her since her first diagnosis, leading her to visit her doctor with imagined conditions, or simply to stare, panicked, in the mirror while feeling around her skin for nonexistent lumps. “You are allowed to think it. I can hear you thinking it,” Crampton notes at the start of A Body Made of Glass. “I am a hypochondriac. Or, at least, I worry that I am, which really amounts to the same thing.” Born out of bruising experience, Crampton’s book is a biographical account of hypochondria – generally defined as excessive worry about serious illness – taking in those who have endured, researched, treated and profited from it. Blending memoir and cultural history, it is lucid, broad in scope, full of nuanced reflection and digs deep into concepts of rationality, language, trauma, the brain v the body, class, gender and the inequity of health services. Crampton – who is a journalist, podcaster and author of The Way to the Sea, about the Thames Estuary – discovers she is in good company: Marcel Proust, John Donne, Charles Darwin, Immanuel Kant, Virginia Woolf and Philip Larkin all struggled with hypochondria, in many cases a by-product of genuine affliction. Having dealt with a lifetime of ailments, imagined and real, the French playwright and actor Molière was moved to write Le Malade Imaginaire (The Imaginary Invalid). It would be his last work since, in 1673, while performing in the play, he collapsed on stage and later died. If all this sounds like a recipe for gloomy introspection, it isn’t. Crampton’s research is underscored by her compassion for hypochondriacs (who are sometimes patronisingly called the “worried well” by medical professionals) and a bleak humour at the daft situations in which they find themselves. There can be no better summation of the hypochondriac’s dilemma than the Irish inscription on Spike Milligan’s headstone: Dúirt mé leat go raibh mé breoite, or “I told you I was ill”. The book’s title refers both to the symbolic role of glass in “the complex knot of emotions and sensations that we now associate with [hypochondria]” and the very real historical figures who believed their bodies were made of glass. One of them was the 14th-century French monarch Charles VI, who kept his advisers at arm’s length and had iron rods inserted into his clothes to protect him from shattering. In the early 17th century, a French physician reported the case of a glassmaker who had come to believe he had glass buttocks and went around with a cushion strapped to his behind; the cure for his delusion came when a doctor grabbed him and beat him hard on the backside, prompting him to concede that it was flesh and blood after all. Such beliefs seem laughable but, for Crampton, the fear of damage or disease is real. “Hypochondria exists at the intersection of those feelings of fragility and transparency experienced by the glass people,” she writes. “We are breakable. We are vulnerable … We are misunderstood, ridiculed, ignored.” There is, of course, a place for health anxiety as an entirely rational response to one’s environment. For early humankind, it was part of “the complex web of adaptations and traits” that enabled our survival. While the immune system offered a wall of protection to early humans, so did the brain, by identifying danger in the form of disease or rotting food, giving them the best possible chance of evading illness. In 2020, precautions around the spread of Covid-19 were seen by most as proportional to the threat. Crampton talks of the peculiar comfort of the early months of lockdown when health anxiety became the norm. In the midst of a global health crisis, hypochondriacs were able to lean in to to their paranoia, which was now sanctioned by health authorities. It will surprise precisely no one to learn the gendered nature of medical treatment and assumed cases of hypochondria. The ancient Greeks believed that the uterus moved around the body – Plato famously described it as “the animal within” – and was the source of all manner of maladies. The earliest known medical text, the Kahun Gynaecological Papyrus, documents the examination of a woman “whose eyes are aching till she cannot see” and assessed her condition as “discharges of her womb in her eyes”. These days, women in pain are still less likely to be believed than men by medical professionals, with women of colour seen as especially unreliable when presenting symptoms. You only need look at the slowness to diagnose cases of endometriosis, in which tissue similar to the womb lining grows outside the uterus, to see how women are dismissed in medical settings or expected to live with pain. Crampton adds that heart disease kills more women than breast cancer yet still it is a condition associated with men. Matters come into focus in the present day with the rise of the “cyberchondriac”, which describes those who glean their medical information via Google searches and invariably find that “a problem searched is a problem amplified”. Compounding modern health anxiety is the multitrillion dollar wellness industry, the roots of which can be found in 18th-century quackery and its peddling of solutions to non­existent problems. Threaded through this comprehensive historical account are Crampton’s own experiences of health-related trauma, and it’s in these moments that the writing moves from scholarly to elegantly poetic. The author recalls a photograph taken of her when she was 17 at a school dance before her tumour was discovered. In it, her skin is luminous and her hair glossy. Yet, she notes, the photo also shows the shadow of a lump above her left collarbone that she hadn’t yet noticed. It was, she says, “visual proof that I had been sick for so much longer than I realised … The body is hard to reckon with: it is intimately present and completely absent at the same time. I exist inside it and yet I cannot know what is happening within.” The innate mystery of the body is at the heart of this book: for all the advances in science, much of it remains unknowable and medical certainty is an illusion – a notion that, for the hypochondriac, can only induce fear. Five years of research into her condition hasn’t yielded a miraculous cure for Crampton. Yet increased understanding has brought a degree of acceptance. Echoing a line by the poet John Donne, written while in the throes of a fever, she observes: “I am ill and I am well. I am still here.” A Body Made of Glass by Caroline Crampton is published by Granta (£16.99). To support the Guardian and the Observer buy a copy at guardianbookshop.com. Delivery charges may apply.