My grandmother, Joan, has always been energetic, prickly, self-reliant. As a girl she loved swimming, cycling, flirting, arguing, dancing, moving. She had a good war, in the way that some women did, its relative freedoms coinciding with late adolescence.

After being widowed in her early 70s she read, travelled, bought herself baubles and may or may not have enjoyed a love affair. She was one of the most active people I have encountered. And, now, at 92, I would like her to die.

Even those who do not remember Joan's fierce individualism would pity the condition in which she now finds herself: tortured into living by a medical system that will not let her go. My grandmother is clearly dying, trapped in some pained transitional state. Her face and body have taken on the skeletal appearance of a memento mori. She sleeps most of the time. When awake, her eyes have a lost look within her stilled body, as if in appeal. She cannot hear and increasingly refuses to eat or drink. She is ready.

The medical services, however, are not, and are engaged in an aggressive battle to resurrect her. The individual they are fighting would appear to be my grandmother herself. Joan has always expressed a desire to die at home, and was paying hundreds of pounds a month painstakingly saved for the privilege, nourished by those who love her in surroundings in which she felt secure.

This summer she was removed from the home she has occupied since 1940 by a district nurse coup – against her wishes, those of her family and GP – and is now on a disorientating, stifling and noisy geriatric ward. Elements of dementia have increased with the confusion. We were told she would be admitted for a maximum of 48 hours. Yesterday, she saw in her fifth week. Benevolent as her immediate nursing staff are, this hijack is one of the most grotesque things I have witnessed – not merely inhumane, but inhuman.

Tony Nicklinson, who died today , last week championed a failed high court attempt to allow doctors to end his life without fear of prosecution. It is a bitter irony that the decision not to permit him to quit life in his preferred circumstances may have contributed to his demise, his family describing him as "heartbroken", the fight having gone out of him. The situation I am proposing is still more fundamental, involving not killing people but letting them die with dignity in conditions of their choosing.

Society is rightfully concerned with the neglect of the elderly. However, using medical science to willfully, perversely keep the aged alive not only against all odds but against any regard for quality of life, may be equally torturous. It was Ivan Illich's Limits to Medicine that first posited the theory of "medicalisation" back in the mid-70s. Illich argued that contemporary medicine had "brought the epoch of natural death to an end". Death was no longer to be considered part of life, instead "total war" waged against it, family care and ritual deemed superfluous.

Our ever-increasing secularisation, homogenising multiculturalism and a culture obsessed with youth have only exacerbated death denial. An immortality topos abounds in which dying is to be indefinitely evaded, the most standard exits routinely described as "tragic".

Where death is the enemy, so the elderly become its substitutes. As Graham Mulley recently wrote in the British Medical Journal: "Medical ageism … now includes over-investigation and subjecting frail elders to unpleasant, unnecessary, and unproved procedures and therapies." While, as German physician Friedemann Nauck has remarked, death in hospital resembles an "industrial accident".

There is an acknowledged crisis over how we treat the elderly. However, there is no less a moral crisis in how society thinks about such issues. In the literature surrounding "a good death", the stereotype is of a patient or family who refuse to come to terms with the end. Where geriatric patients are concerned, this reluctance would appear to be on the part of the medical profession itself.

Quality of death needs to be restored to its proper place as part of quality of life. After all, as the great medical communicator Professor Petr Skrabanek observed: "Life itself is a universally fatal sexually transmitted disease."