What causes hay fever?
Hay fever occurs when your immune system overreacts to the inhalation of harmless allergens such as pollen, dust or pet dander, releasing substances called histamines into the bloodstream to ‘protect’ your body from these allergens.
These histamines are behind the inflammation of the nasal passage, sinuses and eyelids, causing congestion that, while intended to stop the allergens from getting into your body, actually causes discomfort and irritation.
Seasonal hay fever typically occurs in spring and summer, caused by the extra pollen in the air.
In the spring, pollen from trees is the usual suspect for triggering hay fever, while grass and weed pollen are much more likely to be behind the allergy in the summer.
In these months, pollen is in abundance in the air and can easily be inhaled, causing an allergic reaction within the nose and sinuses. Eyes can also be affected by pollen that gathers on them or on the skin around them, leading to discomfort and irritation.
For sufferers of perennial hay fever, allergies are more likely to be caused by other allergens than pollen. These other allergens can include dust, mould and pet dander.