Hay fever is essentially a mistaken immune system reaction to airborne particles, which normally do not cause the body any trouble. These particles may be pollen, animal dander, dust, mold, or insects and their feces. Most people inhale these without a problem.
People with allergies inhale these and the body reacts as if it were being invaded by a pathogen. There is sneezing, runny nose, red, itchy, watering eyes, headache & even asthmatic contraction of the bronchioles of the lungs leading to panting, wheezing & coughing.
Western medicine treats hay fever and other respiratory allergies by a combination of antihistamines and decongestants. Although the side effects of these Western drugs are less than they used to be, many patients do not want to stay on such drugs for long periods of time. Happily, Chinese medicine provides a time-tested alternative to Western drugs when it comes to the treatment of hay fever and other allergies.