Most of us have had seasonal allergy symptoms, also known as hay fever. During growing seasons, plants spread pollen through the air and, when breathed in, can be seen as a threat by your body. This will then cause an allergic reaction.
Some plants, such as ragweed, mountain cedar, and sagebrush, are worse than others for causing allergies. Allergies are also caused by grass pollen and tree pollen, especially birch, cedar, and oak.