I've never been terribly hot at languages. At school I was taught French and Latin, though struggled with both.

Most of the Latin  phrases I recall learning were about as useful as a chocolate teapot - such as ‘Labienus and Cotta, having been besieged by the Carthaginians, went forth.' Nevertheless, this apparently dead language has come in handy in being able to make sense of some of the longer words that the medical profession delights in, such as pneumonoultra- microscopicsilicovolcanoconiosis, which I am assured is genuine.

There are great advantages and disadvantages in having English as one's native tongue. There is so much less incentive to study a foreign language when so many people around the world have apparently mastered English.

But it's all too easy to assume that understanding exists when it doesn't. If America and Britain are two nations divided by a common language the same can also be said about doctors and patients.

The classic example of language being used entirely differently on opposite sides of the medical divide must be the way we use the word chronic. Like me, I'm sure you've had patients who come in and tell you they've had this absolutely chronic backache for a couple of days or a chronic headache since this morning. Whereas doctors use chronic with an entirely different meaning.

I had a typical example only yesterday. This patient has always worried intensely about her health. Each and every symptom spells disaster, and she is always on the lookout for nuances in the way that I phrase things that confirm her very worst fears. And on this occasion, she had the evidence.

For ages she has suffered from backache, and a couple of weeks ago had been seen in the local pain clinic. She came into my consulting room brandishing a copy of the clinic letter that had been sent to her. ‘Look at this,' she said. ‘The consultant says my condition is chronic. I'm absolutely terrified now. What's going to happen?'

Chronic is clearly a word that many patients think means really bad, or really serious. Doctors don't.

If the function of language is to help us communicate, and both parties are using words in entirely different ways, is there any hope at all of real communication? So should we abandon using words such as chronic altogether?

Pneumonia is another example of a word that carries two very different meanings. To doctors, it means a chest infection. To many patients being told they have pneumonia is like being given a death sentence. People die of pneumonia. I've got pneumonia. Therefore - it follows - I'm going to die.

As a result, it's a word I have almost abandoned using, as it may be medically accurate, but can communicate entirely the wrong message. When patients, particularly elderly patients, are critically ill - it is a word that can certainly convey the gravity of the situation to relatives - but for most people it is often met with fear quite unnecessarily.

Lewis Carroll got it right in Through the Looking Glass when Humpty Dumpty says: ‘When I use a word it means just what I choose it to mean - neither more nor less.'

The trouble is we all do exactly that - both doctors and patients.