TreatAllergies.com

"Hayfever", or "hay fever", is the commonly used word for the medical condition allergic rhinitis, where "rhinitis" describes the inflammation of the nasal mucous membranes and "allergic" means that it is caused by an allergy. The term "hayfever" was coined over a century ago when English doctors noticed that people suffered sneezing fits, itchy eyes and a runny nose during the hay making season. It is a misleading term because the symptoms are not only restricted to the times when hay was traditionally gathered and they do not include a fever.

There are two main types of allergic rhinitis:

• Seasonal allergic rhinitis or hayfever in everyday usage, usually occurs in spring or early summer when the pollen from trees and grass becomes airborne. In autumn, the trigger for allergic rhinitis is more likely to be pollen from weeds and mould spores.
  
  
• Perennial allergic rhinitis affects sufferers all year round and is caused by indoor allergens like animal dander (animal hair or skin debris), moulds and dust mites. These allergens are difficult to avoid for those people who are sensitive to them. Symptoms include an inflammation of the inner lining of the nose.

Hayfever is a fact of life for many people in the world. It can prevent sufferers from going about their day normally, leaving them unable to work, drive or concentrate. The number of people who suffer from hayfever is on the rise as the worldwide rates for hayfever and asthma increase. One theory is that this rise in the incidence of hayfever is due a combination of summer starting earlier and an increasing amount of pollution in many areas of the world. The warmer climate created by global warming encourages plants to pollinate earlier, while more pollution traps this pollen in the atmosphere for longer.

It has been estimated that hayfever affects about 20% of the population in Britain. Many people, about a third of these, develop hayfever as children before the age of ten. While hayfever may begin at any age, the allergy is usually developed prior to the age of 20 years. Often sufferers notice that the condition gets worse in the first couple of years before stabilising. Sometimes people with hayfever experience fewer symptoms as they grow older, to the point where it ceases to affect them. An estimated 26 to 30 million Americans are affected by hayfever symptoms each year. In New Zealand, the large amount of greenery results in a very high incidence of hayfever, with around one in six people being sufferers.