A Question Of Health: What exactly is pneumonia? And is salt a necessary part of a healthy diet?

Over the last few months, a number of elderly people I know have died as a result of pneumonia or bronchial pneumonia

IGNORANCE ISN'T BLISS

Over the last few months, a number of elderly people I know have died as a result of pneumonia or bronchial pneumonia. When I have mentioned this to people they all give the impression that they know what pneumonia is, but when questioned further they have to confess their ignorance. I have tried to use the internet to give me some insight, but have been unsuccessful. In my experience it appears that pneumonia has a rapid onset and is treatable with antibiotics. Is it possible to identify the symptoms of pneumonia in the early stages and therefore take some preventative measures to minimise the risk, particularly to the elderly? Is there anything that would help to prevent the illness arising in the first place? What is the difference between pneumonia and bronchial pneumonia?

Pneumonia is an infection of the lung. Bronchial pneumonia is no different, but the word bronchial implies that the infection has started in the small tubes - the bronchi and bronchioles - that carry air in and out of the lungs. The body's reaction to bacterial infection is to produce pus, and this clogs up the tubes and the tiny air sacs within the lung. An infection that is confined to the tubes is called bronchitis. Once harmful bacteria take hold within the lung, the infection can spread quite quickly, particularly in the elderly or in those who have poor immunity. Antibiotics kill bacteria, and even old-fashioned antibiotics like penicillin save the lives of many people who contract pneumonia. One excellent preventative measure is a vaccination against influenza, particularly in elderly people. Influenza infection, which is caused by a virus, increases the risk of getting pneumonia, which is caused by bacteria. The whole idea behind preventing the flu is to prevent the more serious complications that arise from it.

SALTING AWAY TROUBLE?

I am an 80-year-old vegetarian, and for several years I have been troubled by very itchy skin caused by allergies or intolerances. When it became worse last year, I went on an elimination diet - the result of which was to severely restrict my range of food. With the addition of food supplements, I feel that my diet is nourishing, except that I have to avoid all food that contains any salt. It is now more than a year since I took salt except by accident, when I get the itch. Apart from this I enjoy good health. Can you please tell me whether or not additional salt is a necessary part of the diet?

Although your elimination diet has restricted the amount of salt that you are consuming, it is impossible to have a diet that is completely salt-free. I am therefore a little surprised to hear that your skin gets worse when you accidentally take some. But I won't argue with success, and if your skin doesn't itch on your current diet, it may be sensible to carry on with it. There is no biological reason why you need to add salt to your diet. Many foods contain sodium and chloride (the chemicals that make up table salt), and you will be getting enough simply by eating a reasonably mixed diet.

HAIRY MONSTERS

I know how to get rid of the horrible white slime - or fur - that appears on my tongue from time to time (bicarbonate of soda), but I don't know why it appears. Is it a sign of ill-health? And what exactly is it? Where does it come from?

Slimy tongues that are coated with white, grey or even black fur are sometimes given the diagnosis of "black hairy tongue". It's caused by a combination of factors, including bacterial overgrowth, smoking and other things that change the micro-environment of the tongue. Red wine, which contains enzymes that can add to the problem, seems to make things worse in some people. Another factor is taking antibiotics, which change the balance of bacteria and other organisms, such as fungi, allowing unfriendly organisms to overgrow. The treatment that you use makes your mouth more alkaline (the opposite of acidic). It is probably the best available, but try to avoid the smoke and red wine. You might even find that a brief mouthwash with warm water and a pinch of salt each morning and evening keeps the fur at bay. Black hairy tongue is not a sign of ill health, although it may mean that something is slightly out of balance.

HAVE YOUR SAY: READERS WRITE

Advice for a menopausal migraine sufferer, from TH of Colchester:

The 49-year-old with migraine should not take beta-blockers, antidepressants or the like without finding out whether her diet is the cause. Food triggers are a major cause of migraine headaches - this and other unpleasant side effects of the menopause can be more or less eliminated without resorting to HRT.

A consultant neurologist from London offers a possible explanation for the incorrect advice that you mustn't drink alcohol when you are taking antibiotics:

A venereologist may have dreamt up the idea of "no booze on antibiotics". If you have syphilis, tests are corrupted by catching a second dose of the disease while on treatment. It is unusual to catch sexually transmitted diseases while sober - so, no alcohol means no re-infection while on antibiotics.

Please send your questions and suggestions to A Question of Health, 'The Independent', Independent House, 191 Marsh Wall, London E14 9RS; fax 020-7005 2182 or e-mail health@independent.co.uk. Dr Kavalier regrets that he is unable to respond personally to questions