I'm Professor Peter Barnes,

head of respiratory medicine at Imperial College, London,

and consultant physician at the Royal Brompton Hospital in London.

If I were diagnosed with asthma,

I'd want to know what the long-term prospects are for the disease,

and whether there might be any problems with treatments.

I think the advice to give to people that think they might have asthma

is to go and see your GP,

because they will be able to diagnose it,

and start you on appropriate therapy straight away.

Asthma's an extremely common condition

that is most obviously shown by wheezing and shortness of breath,

and is due to narrowing of the air tubes,

so that patients are feeling uncomfortable,

because the air tubes are constricted,

and they feel they can't get enough breath.

The particular nature of asthma

is that these symptoms tend to be variable.

Sometimes they're there, sometimes they're not.

Some patients experience very severe attacks,

and need to go to hospital for special treatment.

So I think this is quite a frightening condition for patients,

at least when it first starts.

Well, asthma is extremely common in children.

In fact, it usually first becomes apparent

when children are aged about three or four.

It can be very frightening to the parents,

because the child may suddenly become very ill.

So it's important to make the diagnosis as soon as possible,

so that the right treatment can be started.

Unfortunately, there's no cure for asthma,

but the vast majority of patients

can be controlled for most of the time using currently available treatments.

There are two types of treatment.

The first kind is called relievers that relieve symptoms.

But the most important treatments are called controllers,

and these control the underlying disease.

By far the most effective controllers that we have are inhaled steroids.

Inhaled steroids are very safe and very effective,

and have revolutionised the management of asthma.

For some patients, we now give steroids

in combination with a long-acting reliever,

and this combination is very effective.

Many patients are worried about having side effects of taking steroids,

but the doses that we need to use for most people are actually very low,

and they're not causing any long-term problems.

Asthma seems to be increasing throughout the world, in every country.

It seems to be linked to westernisation of countries.

So something about the western lifestyle

is associated with this increased amount of asthma.

The sort of factors that may be important are changes in diet

with less fresh fruit, for example,

air pollution,

and the fact that people are less likely to have infections during childhood,

because infections in early childhood

seem to give you a protective immune system against asthma.

So probably it's a combination of all of these factors.

Asthma treatment in the UK is extremely good,

and I'd say it's probably among the best places in the world

for treatment of asthma.

That's because it's mainly managed in general practice

where it should be managed, as it's a common disease,

and the system of specialist asthma nurses in general practice

has worked extremely well,

because they have time to talk to the patients,

to teach them about their disease,

how to use their treatments, and to follow the patients up.

It's a very, very effective system.