Millions of people all over the world suffer from hay fever, which is an allergy to pollen resulting in irritating symptoms like a runny nose and watering eyes.
It's often unavoidable as the weather gets warmer, with plenty of people stocking up on antihistamines in preparation for the higher levels of pollen in the air.
But if your hay fever is particularly bad or the pollen count has skyrocketed, you might find that medications don't do enough to keep your symptoms under control.
