Hay fever symptoms vary in severity and may be worse some years than others, depending on the weather conditions and the pollen count. The time of year your symptoms start depends on the types of pollen you're allergic to.

The symptoms of hay fever include:

• frequent sneezing
• runny or blocked nose
• itchy, red or watery eyes (also known as allergic conjunctivitis)
• an itchy throat, mouth, nose and ears
• cough, caused by postnasal drip (mucus dripping down the throat from the back of the nose)

Less commonly, you may experience:

• the loss of your sense of smell
• facial pain (caused by blocked sinuses)
• headaches
• earache
• tiredness and fatigue

While symptoms of hay fever may be mild, they can interfere with your sleep and your daily activities at school or work.

Hay fever and asthma

If you have asthma, your asthma symptoms may get worse when you have hay fever. Sometimes, asthma symptoms only occur when you have hay fever.

These symptoms include:

• tight chest
• shortness of breath
• coughing
• wheezing

Pollen count

Hay fever symptoms are likely to be worse if the pollen count is high. The pollen count is the number of grains of pollen in one cubic metre of air.

Air samples are collected in traps set on buildings two or three storeys high. Taking samples from this height gives a better indication of the pollen in the air.

Traps on the ground would only collect pollen from nearby trees and plants.

The air is sucked into the trap and the grains of pollen are collected on either sticky tape or microscope slides (glass plates). The pollen is then counted. Samples are normally taken every two hours, and usually the results are averaged over a 24-hour period.

The pollen forecast is usually given as:

• low: fewer than 30 grains of pollen in every cubic metre of air
• moderate: 30-49 grains of pollen in every cubic metre of air
• high: 50-149 grains of pollen in every cubic metre of air
• very high: 150 or more grains of pollen in every cubic metre of air

Hay fever symptoms usually begin when the pollen count is over 50. The pollen count is usually given as part of the weather forecast during the spring and summer months.

When to seek medical advice

Most cases of hay fever can be treated using over-the-counter medication.

A pharmacist can advise on treatments for you or your children.

You would normally only need to see your GP if:

• you can't control your symptoms with over-the-counter medications or you are having troublesome side effects caused by the medication
• you are experiencing persistent complications of hay fever, such as worsening of asthma or repeated episodes of sinusitis
• the pattern of your symptoms is unusual; such as occurring during the winter or only at your workplace – it is likely that another substance other than pollen is responsible and further testing will be required to confirm this

Allergen

An allergen is a substance, such as pollen, that reacts with the body's immune system and causes an allergic reaction.

Allergy

Allergy is the term used to describe an adverse (bad) reaction that the body has to a particular substance.

Pain

Pain is an unpleasant physical or emotional feeling that your body produces as a warning sign that it has been damaged.

Sneezing

Sneezing is an involuntary expulsion of air and bacteria from the nose and mouth.

Wheezing

Wheezing is the whistling sound made during breathing when the airways are blocked or compressed.