Many people will like Lionel Shriver's ninth novel  admirers of gripping and clever contemporary fiction, discerning critics and, if there is any justice, literary prize committees. But there is one group to whom So Much for That cannot possibly be recommended: hypochondriacs.

Shep Knacker, a New York-based hardware company executive, is planning to use his accumulated investments ($731,778.56 as the book begins) to fund a sabbatical at the African paradise resort of Pemba Island near Zanzibar, when his wife, Glynis, reveals that she has been diagnosed with peritoneal mesothelioma, a rare form of cancer. In the alternating chapters, the couple's best friends, Jackson and Carol, have a daughter suffering from familial dysautonomia, a congenital condition that arrests digestion and development.

As a result, when one character isn't having "two ports in your abdomen . . . [to] deliver intraperitoneal infusions of heated cisplatin", another is undergoing a "Nissen fundoplication to cure chronic acid reflux". A typical conversation takes place through "a throat raw from intubation". Two of the story's supporting cast also have major surgery, with one undergoing a procedure that should be restricted reading not only for hypochondriacs but for any man at all. The only person in the narrative who is in perfect health has convinced herself she is ill and so been prescribed sugar-pill placebos in order not to feel left out.

This book's critically underrated predecessor, The Post-Birthday World, gave a woman two alternating versions of her life after a relationship decision. So Much for That continues Shriver's interest in chance, though the incidence of medical catastrophe among the cast list might initially be thought to be pushing the laws of probability. It soon becomes clear, though, that it is vital to the story's theme that the characters be seeking treatment. Published in the week that President Obama's attempt to reform American medical coverage reached its legislative climax, So Much for That spine-tinglingly dramatises the reality of falling sick in the US.

Without ever seeming contrived for polemical purposes, Shriver's narrative strands systematically illustrate the traps of provision by private health insurance companies. Shriver's characters do jobs they dislike  Shep is humiliated daily in a company he once owned  because their companies cover their medical bills, at least in theory. But as Glynis's treatment goes on, her husband's Merrill Lynch savings account shrinks far faster than her tumours, its falls grimly documented at the beginning of each chapter. Because the surgeon with the best outcomes is not on their policy's list of approved carers, Shep is forced to become a "co-insurer", a euphemism for paying out even though he is paid up.

Carol and Jackson have less immediate difficulties but are queasily aware that, by being foolish enough to be born sick, their daughter will soon use up her lifetime limit for treatment. And, like the Knackers, they discover that many of the procedures Flicka needs are more expensive than the "reasonable and customary" fees their insurer will meet, an optimistically low figure which turns out to be decided by a subsidiary of the healthcare provider. In its demonstration of the human consequences of public policy, Shriver's novel does for medicine what The Jungle by Upton Sinclair did for the Chicago meat industry.

The book, though, is as much psychological as political, inspecting its characters' attitudes to illness and death. The previously selfish Shep, for example, behaves towards Glynis in a way he considers saintly, but she rebukes him for becoming "just another service provider". Throughout, illness convincingly mutates the behaviour of both patients and carers.

Depressingly, the early reception of the book in Britain turned not on a system that condemns millions of Americans to penurious suffering but the ethical "issue" of Shriver's location-placement of Fundu Lagoon on Pemba Island, a real resort where she accepted hospitality. But novelists are not members of parliament, and this paradise  which the narrative eventually, and ingeniously, reaches  serves as the book's central metaphor. The destination represents the "Afterlife", an escape from work of which Shep dreams and a code that takes on a terrible double meaning after Glynis's prognosis.

Names are the novel's one false note. Shep's full moniker is Shepherd Knacker, an oddly Carry On-ish tag which, with its presumably intended shadow of the yard to which doomed animals go, introduces a note of vulgarity to an otherwise subtle and thoughtful book. The same is true of naming the sick teenager Flicka.

Because of the tense plotline of the Orange prize-winning We Need to Talk About Kevin, Shriver is most often complimented for her narrative power and journalistic detail. Though both are present in So Much for That, there is also so much more: her control of free, indirect style, switching between viewpoints of different ages and genders, is impeccable. Shep realises that he is suffering from "that distinctive middle-class covetousness, desire for what you already own". Carol reflects that being the mother of a sick child is "like being a doctor yourself but without the golf. You were always on call."

As Obama signs his healthcare bill into law, this hugely impressive novel deserves a long and healthy life, insuring universal pleasure and thought for readers.

Mark Lawson's Enough Is Enough, or The Emergency Government is published by Picador.

Many people will like Lionel Shriver's ninth novel  admirers of gripping and clever contemporary fiction, discerning critics and, if there is any justice, literary prize committees. But there is one group to whom So Much for That cannot possibly be recommended: hypochondriacs.

Shep Knacker, a New York-based hardware company executive, is planning to use his accumulated investments ($731,778.56 as the book begins) to fund a sabbatical at the African paradise resort of Pemba Island near Zanzibar, when his wife, Glynis, reveals that she has been diagnosed with peritoneal mesothelioma, a rare form of cancer. In the alternating chapters, the couple's best friends, Jackson and Carol, have a daughter suffering from familial dysautonomia, a congenital condition that arrests digestion and development.

As a result, when one character isn't having "two ports in your abdomen . . . [to] deliver intraperitoneal infusions of heated cisplatin", another is undergoing a "Nissen fundoplication to cure chronic acid reflux". A typical conversation takes place through "a throat raw from intubation". Two of the story's supporting cast also have major surgery, with one undergoing a procedure that should be restricted reading not only for hypochondriacs but for any man at all. The only person in the narrative who is in perfect health has convinced herself she is ill and so been prescribed sugar-pill placebos in order not to feel left out.

This book's critically underrated predecessor, The Post-Birthday World, gave a woman two alternating versions of her life after a relationship decision. So Much for That continues Shriver's interest in chance, though the incidence of medical catastrophe among the cast list might initially be thought to be pushing the laws of probability. It soon becomes clear, though, that it is vital to the story's theme that the characters be seeking treatment. Published in the week that President Obama's attempt to reform American medical coverage reached its legislative climax, So Much for That spine-tinglingly dramatises the reality of falling sick in the US.

Without ever seeming contrived for polemical purposes, Shriver's narrative strands systematically illustrate the traps of provision by private health insurance companies. Shriver's characters do jobs they dislike  Shep is humiliated daily in a company he once owned  because their companies cover their medical bills, at least in theory. But as Glynis's treatment goes on, her husband's Merrill Lynch savings account shrinks far faster than her tumours, its falls grimly documented at the beginning of each chapter. Because the surgeon with the best outcomes is not on their policy's list of approved carers, Shep is forced to become a "co-insurer", a euphemism for paying out even though he is paid up.

Carol and Jackson have less immediate difficulties but are queasily aware that, by being foolish enough to be born sick, their daughter will soon use up her lifetime limit for treatment. And, like the Knackers, they discover that many of the procedures Flicka needs are more expensive than the "reasonable and customary" fees their insurer will meet, an optimistically low figure which turns out to be decided by a subsidiary of the healthcare provider. In its demonstration of the human consequences of public policy, Shriver's novel does for medicine what The Jungle by Upton Sinclair did for the Chicago meat industry.

The book, though, is as much psychological as political, inspecting its characters' attitudes to illness and death. The previously selfish Shep, for example, behaves towards Glynis in a way he considers saintly, but she rebukes him for becoming "just another service provider". Throughout, illness convincingly mutates the behaviour of both patients and carers.

Depressingly, the early reception of the book in Britain turned not on a system that condemns millions of Americans to penurious suffering but the ethical "issue" of Shriver's location-placement of Fundu Lagoon on Pemba Island, a real resort where she accepted hospitality. But novelists are not members of parliament, and this paradise  which the narrative eventually, and ingeniously, reaches  serves as the book's central metaphor. The destination represents the "Afterlife", an escape from work of which Shep dreams and a code that takes on a terrible double meaning after Glynis's prognosis.

Names are the novel's one false note. Shep's full moniker is Shepherd Knacker, an oddly Carry On-ish tag which, with its presumably intended shadow of the yard to which doomed animals go, introduces a note of vulgarity to an otherwise subtle and thoughtful book. The same is true of naming the sick teenager Flicka.

Because of the tense plotline of the Orange prize-winning We Need to Talk About Kevin, Shriver is most often complimented for her narrative power and journalistic detail. Though both are present in So Much for That, there is also so much more: her control of free, indirect style, switching between viewpoints of different ages and genders, is impeccable. Shep realises that he is suffering from "that distinctive middle-class covetousness, desire for what you already own". Carol reflects that being the mother of a sick child is "like being a doctor yourself but without the golf. You were always on call."

As Obama signs his healthcare bill into law, this hugely impressive novel deserves a long and healthy life, insuring universal pleasure and thought for readers.

Mark Lawson's Enough Is Enough, or The Emergency Government is published by Picador.