pollenPollen is a fine grain produced by the male flowers of a plant and then transported to the female flower for fertilization and reproduction. Methods used for transportation are:

  • Insects, such as butterflies and bees
  • Animals, such as hummingbirds and bats
  • Wind

The pollens that cause the majority of hay fever and seasonal allergy symptoms are those that are wind-pollinated, meaning they are carried by the wind to the female flower. To be wind-pollinated they are:

  • Tiny and lightweight. They can easily be carried by the wind for long distances to make sure that the female flowers are fertilized. Scientific reports have documented ragweed pollen as far as 400 miles out at sea.
  • Produced in large quantities. Wind can be an unreliable method of reproduction so trees, grasses, and weeds produce large amounts of pollens to make sure that their female flowers will be fertilized.

What types of pollen cause allergy symptoms?

  • Tree pollens
    • Especially birch tree
  • Weed pollens
    • Especially ragweed
  • Grass pollens

When is pollen season?

While allergy symptoms such as hay fever can occur year-round it usually happens when the pollen you are allergic to is blooming. Blooming season vary between weather, location, and climate but generally:

(For more information regarding pollens and their seasons click here.)

What about cross-reactions?

Some people with pollen allergies experience an itchy mouth after eating raw fruits, vegetables, or nuts. This reaction is called oral allergy syndrome and is often confused with food allergies. Oral allergy syndrome tends to be a milder reaction limited to the mouth unlike food allergies that ranges from mild to severe and can affect the whole body. Oral allergy syndrome is usually associated with birch pollen allergies but can also affect people with allergies to: tree, grass, and weed pollens; and Latex.

  • For a list of the most common cross-reactions between pollens and their foods please click here.
  • For more information about oral allergy syndrome please click here.

For more information regarding diagnosis, treatment, and prevention of pollen-related hay fever symptoms please click here.



Disclaimer: The information contained in this site is for educational purposes only, and should not be used as a substitute for a licensed physician. Please see your physician for diagnosis and treatment of any concerning symptoms or medical condition. Click here to read the full disclaimer.
Subscribe today to receive OASN updates, information, and promotions!