As global temperatures climb and atmospheric carbon dioxide levels rise, many allergenic plants are breaking dormancy weeks earlier than they did just a few decades ago. Trees, like oak and cedar, require a certain amount of time where it is cold before their buds will burst, but warmer winters reduce this chilling period, and elevated CO₂ can further disrupt hormonal signals that regulate dormancy, prompting an earlier and more synchronized flowering. Meanwhile, once active, these same high CO₂ conditions act like a fertilizer, supercharging photosynthesis and encouraging grasses and weeds to produce vastly greater amounts of pollen compared to prior years.

Pollen itself is a powdery reproductive material released by plants when they blossom. In people with seasonal allergies, the immune system mistakes harmless pollen grains for dangerous invaders. In response, it unleashes histamines and other inflammatory chemicals, producing the familiar symptoms of sneezing, runny nose, itchy eyes, nasal congestion and sinus pressure. 

While one cannot prevent plants from pollinating, there are practical steps you can take to reduce one’s exposure and relieve symptoms. Generally, early in the morning and later at night are the times when there is less pollen outside. Rainy days also generally have less pollen, so it is suitable  to go outside then. Also, if running or biking outdoors, consider going at a lesser intensity, as allergies can cause nasal passageways to swell, which reduces the amount of air that can flow into the lungs. Regardless of the weather, it is beneficial to shower and change one’s clothes after going outside. Showering before bed is also important, as pollen can get transferred to one’s bedding and pillowcase, which can exacerbate irritation. Washing bedding and clothing can help in a similar manner. As temperatures get warmer, it is especially important to stay hydrated. In addition to replenishing the water lost from sweating more, hydration can reduce the amount of histamine released by the body and can thin mucus, which is much more effective at trapping allergens. Keeping windows close to limit exposure is also important. If this simple guide does not help you, then you may need to visit a medical professional for further guidance.