allergies and hay fever
Symptoms of an allergy can cause misery and occur when the immune system reacts to an allergic substance which is known as an allergen. The bodies of people who have allergies react to an allergen as if it is being invaded by an unwelcome substance and hence produce a response to fight this substance. It is this immune response which causes the symptoms of an allergy. These symptoms can include sneezing, red and watery/itchy eyes, itchy throat and, less commonly, feeling tired.
Common allergens can be food, mould, dust mite, animal fur and airborne pollutants. Pollen allergy is very common and is known as Hay fever.