For some reason, the immune system of people prone to allergies, misinterprets harmless grains of pollen as a threat to the body, releasing a series of chemicals, including histamine. Unfortunately, this response results in the miserable symptoms we call allergies. Hay fever is not really caused by hay, nor does it produce a fever. The name was coined over a century ago when English doctors noticed that during the hay making season, some people suffered sneezing fits, runny noses and itchy eyes. Hay fever is a seasonal allergic rhinitis because it is caused by plant pollens which are carried on the wind during the growing season.
Antihistamines are more effective if taken as soon as the allergy attack develops.
Taking more than one antihistamine at a time won't bring faster or stronger relief. If your antihistamine isn't effective, you may need to add another type of medication or change brands. Check with your pharmacist or doctor. Don't take antihistamines if you are scheduled for allergy tests within 72 hours. If you are unsure check with your doctor or pharmacist.