When pollen spores dislodge from the plant and become airborne, they can enter your nose and throat. In people who are allergic, pollen triggers a reaction in specialized cells known as mast cells. A mast cell or mastocyte contains histamine, which is released into the bloodstream during an allergic reaction. This causes many of the symptoms associated with pollen allergies — such as runny eyes and nose, nasal congestion, sinus pressure, and itching and irritation.
Allergies are sensitivities to certain substances—including foods, dust, animal dander and pollen— that people come in contact with nearly every day. In normal people, such contact has no ill effects. The bodies of allergic people, however, are sensitive to these substances
Individuals tend to inherit the tendency to have allergies from one or both parents. Though specific allergies, such as a pollen allergy, cannot be inherited, the likelihood of having the same or similar reaction is increased.
Pregnancy, viral infections and puberty can also increase the probability of developing allergies because the body’s defenses and immune system are weakened at these times.
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