Pollens are very samlle particles that are the male fertilizing agent of plants contain protein and chemicals. They carry the male gamete to the female gamete, assisting in the fertilization process. Pollens typically are found in the air and are carried by the wind.

People with allergies to pollens can suffer from a runny nose, itchy eyes, sneezing, or coughing. Some people even get sinus infections. People who suffer from asthma and allergies to pollens may have difficulty breathing or may experience persistent coughing, commonly in the night, evening or morning especially when the weather changes.

Seasonal variation in allergic symptoms occurs because different species of plants pollinate at different times of the year. Geographic locations and climates influence the pollination cycle as well. Pollen counts help allergy sufferers and doctors keep tabs on what, and how much, is floating around. A pollen count represents the amount of specific pollen in an air sample. The time of day and weather conditions affect the pollen count. For example, high winds may increase the amount of airborne pollens. When the pollen count is high, individuals with allergies have more symptoms and are just that much more miserable.

Weeds typically pollinate in late summer, continuing through the fall. This cycle is repeated every year with only mild variation.
You can find out if your symptoms are due to pollens by a skin test to a panel of allergens. Blood tests are used sometimes as well.