Hello, I'm Dr Glenis Scadding.

I work at the Royal National Throat, Nose and Ear Hospital in London

as a consultant allergist and rhinologist.

Hayfever is an allergy.

It's an allergy to pollen,

usually to grass pollen, affecting people in June and July,

but sometimes to other pollens,

tree pollens in the spring and weed and mould pollens in the autumn.

About 100 years ago hayfever was very rare.

It's become increasingly common

and now it affects about one in four of the population.

Diagnosis is usually by the history.

It's pretty easy to recognise

that people who don't have any problems all year round

and who suddenly have problems in June and July have hayfever.

And there's often no need to do any particular test.

If, however, the symptoms are not so clear

or they're on a background of chronic symptoms,

it may be worthwhile undertaking tests

for specific IgE,

that's the allergy antibody against the relevant pollen.

And you can do that on the patient by skin-prick testing.

You can also do it by a blood test.

Hayfever can really steal the summer away from a patient.

If you have a nose which runs every time you go out,

eyes which itch, a nose which blocks up so you can't talk properly,

then the summer becomes a misery

and the patient ends up staying indoors, unable to go out and have fun,

and sometimes even severely affected enough

to be unable to go to work or school.

Hayfever symptoms usually start

once the pollen grains reach a certain level

of about ten grains per cubic millimetre.

They last throughout the season but they will vary from day to day

because the pollen count varies according to the weather.

It will go down if it rains hard or if it's cold,

it'll be high if it's a very warm, sunny day.

Treatments are available for hayfever.

For very mild disease, then an antihistamine taken as required is fine.

And there are perfectly good antihistamines

available over the counter at pharmacists'.

The thing to avoid, though, is taking a sedating antihistamine.

If you do that, then you may be sleepy,

your driving ability may be impaired

and your working and academic ability may also be impaired

even if you don't feel sleepy.

Two puffs again. One up, one back.

For anything more than mild disease,

the first-line treatment of choice is an intranasal steroid spray.

It's very sensible to start this before the hayfever season starts,

at least a couple of weeks before the patient normally gets symptoms,

and it's much better taken every single day without fail.