Hay fever Dr Trisha Macnair About 9 million people in the UK struggle to cope with blocked noses, constant tickly sneezing, watery itchy eyes, headaches, disturbed sleep, listlessness and depression - all symptoms of hay fever, a condition that can last for months.

In this article

Something in the air Weather plays a part

Avoiding trouble Medication

Hay fever, also known as seasonal allergic rhinitis, is a reaction to pollen and fungal spores. Each person with hay fever will show a slightly different pattern of symptoms, depending on the particular pollen or spores they react to.

The hay fever season generally begins with the release of pollen by trees

As different plants come into flower at different times, so the picture of symptoms changes. For example, the hay fever season generally begins with the release of pollen by trees. This may start as early as February and continue to late May. Trees such as birch and oak are particularly to blame.

Most people with hay fever are allergic to grass pollens, which appear between May and September but are at their peak in June and July.

Later in the year, from summer into autumn, levels of weed pollen and fungal spores rise and cause problems.

Keeping an eye on pollen levels (known as the pollen count) and finding out how to minimise exposure are essential parts of the battle against hay fever. Symptoms usually begin when the pollen count exceeds 50.

The pollen count is the number of pollen grains found in each cubic metre of air. But this count doesn't necessarily reflect how many flowers are around. Another crucial factor is the weather, which can determine how much pollen is released from flowers and where it travels to. The amount of sunshine or rain and the speed and direction of the wind are also factors.

Plants release pollen early in the morning

During the pollen season, plants release pollen early in the morning. On a sunny day, as the day gets warmer and more flowers open, pollen levels may rise, and the pollen is carried high into the air. Pollen counts peak at about 5pm to 6pm in the countryside and a couple of hours later in the city.

On very humid and windy days, pollen will spread much further and cause more problems. If it rains, the pollen may be washed or cleared from the air and levels will fall lower than normal.

There are plenty of things you can do to try to reduce your exposure to pollen:

• Watch the pollen count. You can find UK pollen counts at bbc.co.uk/weather.
• Avoid going outside as much as possible when it's humid and windy or when pollen counts are high.
• If you live in a tall building, keep windows closed during the middle of the day, as pollen rises in the atmosphere.
• Protect your eyes from pollen with sunglasses.
• Keep car windows shut as much as possible.
• Don't put washing out to dry if counts are high as pollen may get trapped in the fibres of clothes and bed linen.
• Plan your garden carefully. Choose low-risk plants and get someone else to cut the lawn. Send out a fine spray on the hose sprinkler before you go in the garden to dampen down pollen in the air.
• Wipe down pets with a damp towel after they've been out in the garden, as they may pick up pollen on their fur.
• Before you go to bed, have a shower to get rid of any pollen caught on your body or hair.
• Think carefully about holidays. Pollen levels may be lower on the coast because sea breezes blow it inland.

Many people with hay fever find that medicines are essential to help them through the season. The main treatments are:

• Antihistamines - these inhibit the effects of histamines, which are released during an allergic reaction and cause the symptoms of hay fever.
• Steroids - reduce inflammation in the nose or eyes.
• Sodium cromoglycate - prevents allergic reactions in the nose and eyes.
• Decongestants - a short sharp dose may help to unblock the nose, but can make the problem worse if used long-term.
• Desensitisation - a form of vaccine against pollen, which involves a long course of injections containing very tiny amounts of pollen so the body can learn to deal with it without a reaction.

Always talk to your doctor and pharmacist to find out which medication might suit you best.

This article was last medically reviewed by Dr Rob Hicks in December 2006.