Most doctors fall into one of two categories: the smaller, who are excessively concerned with their health and regard each bodily sensation as the harbinger of serious disease, and the larger, who neglect it and ignore their symptoms altogether.

I belong to the latter. When I was a young man, for instance, I failed to recognise the symptoms of pneumonia and ignored them until I could hardly breathe. For me, doctors treated illness; they did not suffer from it themselves.

Even more difficult for many doctors is illness among their close relatives. How far should they interfere with diagnosis and treatment, at the risk of antagonising their colleagues? If they interfere, they might be regarded as difficult and obstructive; if they do not, they may overlook serious and even life-threatening mistakes.

A doctor recounts her experience in a recent edition of the New England Journal of Medicine. Her aged father collapsed at home while she happened to be there; he had recently had a quadruple bypass operation. His blood pressure had fallen dramatically.

At the hospital he was diagnosed with dehydration and given intravenous fluids. For a time his blood pressure improved and he felt better. Then his blood pressure dropped again. His daughter called a nurse who increased the fluids and for some reason switched off the alarm of the blood pressure monitor. Then she left.

When her father’s blood pressure dropped yet again, his doctor daughter went to the nursing station to inform the medical team. There she was more or less cold-shouldered, and because she did not want to appear one of those “difficult” relatives who seem to think that their loved one is the only patient the hospital has to look after, she did not insist. After all, doctors and nurses have many subtle or unconscious (and sometimes not so subtle or unconscious) ways of wreaking revenge on those whom they consider to have caused them unnecessary grief.

The medical team had overlooked one of the most obvious causes of loss of blood pressure in this case, namely internal haemorrhage. The patient was on anticoagulants after his cardiac surgery, and such a complication is not uncommon. His daughter decided to examine him herself by means of a rectal examination and found that he was indeed bleeding intestinally.