Hayfever

Hayfever is on the increase, but, as pharmacies stock up on a plethora of remedies, which should sufferers take? How can it be avoided? And what causes it in the first place? BBC News Online investigates.

The cause

Hayfever is an allergy to pollens - the male reproductive parts of plants - from grasses and trees.

When they come into contact with the tissue inside the nose, they trigger an immune reaction that can cause congestion, sneezing, itching, and a runny nose.

It is more common during the summer when the levels of pollen are highest.

It can also be triggered by moulds, which are likely to be found in rainy or humid areas.

The treatment

There are three types of treatment - anti-histamine tablets, nasal steroid sprays and anti-allergy injections.

Many anti-histamine tablets are available over the counter in chemists. They knock out the body's immune system, preventing the pollens from eliciting an uncomfortable response.

DEALING WITH HAYFEVER Avoid going outside Keep windows closed Sunglasses can keep pollen out of eyes Shower before bed to clean off pollen Avoid cutting the grass

There are two types of anti-histamine - those that cause drowsiness and those that do not. The non-sedating type are more expensive.

Nasal sprays are only used on the affected area, and leave the rest of the immune system alone. They need to be applied twice a day.

Anti-allergy injections are only used in particularly severe cases and are given over a number of years. They offer long-term protection from allergies.

Which treatment should I use?

Muriel Simmons, chief executive of the British Allergy Foundation, said sprays are best for short-term protection.

However, it depends on the individual's needs, and that should be judged by a visit to a GP, she said.

"We advise hayfever sufferers to go to their doctors and discuss it with them," she said.

"There is a recognised link between hayfever and asthma so you need to monitor it.

"A lot of people who go on to develop asthma have nasal problems but they don't recognise it, they just think 'oh, I seem to go from one cold to another' but in fact they're suffering from rhinitis - which gives you the drippy nose in hayfever."

She said it was better to act sooner than later.

"The major problem is that people leave it too late - they wait until the symptoms start before they take the medication," she said.

"They actually need to take it from about three to four weeks before the season starts."

The pollen season varies by plant, with trees starting first then grasses then weeds. Its timing also depends on location - the further north, the later it comes.

In the UK, trees start in February with grasses running through the summer and mould spores present until October.

Some people say they have achieved relief from symptoms by using homeopathic remedies.

Why are more people getting hayfever?

The most likely explanation is a combination of summer starting early and the increasing rates of pollution.

Ms Simmons says pollution traps the pollen in the atmosphere and holds it there.

"Because we have so much pollution, that's holding it down, and we're all becoming that little bit more sensitive," she said.

The warmer weather has also been blamed, as it tricks plants into pollinating early.

This page contains basic information. If you are concerned about your health, you should consult a doctor.