• May — grass pollen

• August, September — ragweed pollen

• Late fall — turning on hot air furnace, dust

• In bed at night — sometimes the pillows (feathers or even fabric).

If your allergy lasts throughout the year (perennial allergy), it may be due to household dust, animal dander, molds or even food sensitivity. However, many times the cause of seasonal or perennial allergies can be hard to pinpoint, so allergy testing may be in order.