What is hay fever?

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Pollen is the name given to the fine powder that is produced by plants, trees or flowers to fertilise other plants, trees or flowers of the same species. Strictly speaking, hay fever is caused by an allergy to grass or hay pollens. Grass pollen is the most common cause and tends to affect people every year in the grass pollen season from about May to July (late spring to early summer). However, the term is often used when allergies are caused by other pollens such as tree pollens. Tree pollens tend to affect people from March to May (early to late spring) each year. Other people may be allergic to weed pollens (including nettles and docks). Weeds tend to pollinate from early spring to early autumn.

Symptoms are due to your immune system reacting to the pollen. Cells on the lining of the nose and eyes release histamine and other chemicals when they come in contact with pollen. This causes inflammation in the nose (rhinitis) and eyes (conjunctivitis). Sometimes the sinuses and throat can also be affected.

Hay fever is also called seasonal allergic rhinitis because symptoms tend to occur at the same time, or in the same season, each year.

Who gets hay fever?

Hay fever is very common. It affects 2 in 10 people in the United Kingdom. It often first develops in school age children and during the teenage years. Symptoms return for a season each year, but it eventually goes away or improves in many cases (often after having had symptoms each season for several years).

Hay fever tends to run in families. You are also more likely to develop hay fever if you already have asthma or eczema. Equally, if you have hay fever, you are more likely to develop eczema or asthma. The conditions asthma, eczema and hay fever are known together as 'atopic' conditions or 'atopy'. A tendency to atopy can run in families.

What are the symptoms of hay fever?

The symptoms of hay fever can vary from person to person. Some people only have mild symptoms that tend to come and go. Others can be severely affected with symptoms that are present every day during the pollen season.

Common symptoms - These include a runny and itchy nose, a blocked nose, sneezing, itchy and watery red eyes, and an itchy throat. In some cases only nose symptoms occur, and in some cases only eye symptoms occur.
Less common symptoms - These are loss of smell, face pain, sweats, and headache.
Asthma symptoms - Symptoms such as wheeze and breathlessness may get worse if you already have asthma. Some people have asthma symptoms only during the hay fever season. If you have hay fever, you are more likely to develop asthma.

The symptoms may be so bad in some people that they can affect sleep, interfere with school and exams or interfere with work.

Will it help if I avoid pollen?

It is impossible to totally avoid pollen. However, symptoms tend to be less severe if you reduce your exposure to pollen. The pollen count is often given with TV, radio, internet, or newspaper weather forecasts. The following may help when the pollen count is high.

Stay indoors as much as possible, and keep windows and doors shut.
Avoid cutting grass, large grassy places, and camping.
Shower and wash your hair after being outdoors, especially after going to the countryside.
Wear wrap-around sunglasses when your are out.
Keep car windows closed, and consider buying a pollen filter for the air vents in your car.

How is hay fever diagnosed?

You doctor or nurse can usually diagnose hay fever from your typical symptoms that can occur during the hay fever season. They may also ask if there is a history in your family of hay fever, asthma or eczema.

If hay fever is suspected, your doctor or nurse will usually suggest treatment for your symptoms (see below). If the symptoms respond to treatment, this can help to confirm the diagnosis. In rare cases when the diagnosis is in doubt, your doctor may suggest blood tests or skin prick testing to confirm your pollen allergy. See separate leaflet called 'Skin Prick Allergy Test' for further detail.