show up at the same time of the year every year and are caused by exposure to pollens from trees, grasses, or weeds. Hay fever is the most common seasonal allergy.
Allergies that occur for more than 9 months out of the year are called perennial allergies. Between 20 and 40 million people in the United States are affected by perennial allergies.
Year-round symptoms (chronic allergies) are most likely to occur from exposure to animal dander, house dust, or mold.
Use the Check Your Symptoms section to decide if and when you should see a doctor.
