Hayfever is a common allergic reaction that affects up to one in five people at some point in their lives, according to NHS Choices. The condition is more common in boys than girls, but affects adult men and women equally. It is also more likely to affect those with a family history of allergic conditions, particularly asthma or eczema.

These susceptible individuals are sometimes described as 'atopic', meaning they have an inherited predisposition that makes them more likely to develop an allergic disorder at some point in their lives. Hayfever rates are on the rise and, according to Allergy UK, symptoms are now appearing for the first time at any age, not just during childhood or teenage years, for reasons which experts can't fully explain.

Some believe that climate change could play a role, as rising carbon dioxide levels may make plants grow more efficiently and produce more pollen. Others think that cleaner lifestyles could be to blame as our immune systems encounter fewer germs and therefore overreact to non-harmful substances, like pollen. Increased urbanisation and air pollution have also been suggested as potential culprits. Whatever the cause, there is no doubt that hayfever can have a significant impact on a sufferer's quality of life.

According to NHS Choices, a third of adults with hayfever say that their symptoms have a considerable negative impact on their work, home and social life, while child sufferers often find that their symptoms impact on their schooling, which can delay their learning and development. The Allergy UK report 'The Missing Link' states that many teenage allergy sufferers will drop at least one grade in their exams because of their allergy.