Spring means beautiful flowers, fragrant lilacs – and lots of tree pollen coating cars and setting off sneezing, wheezing and headaches.

As an allergist and immunologist at the University of Colorado School of Medicine, I help patients with seasonal allergies and associated allergic diseases manage their conditions, and one question comes up year in and out: Will this season be worse than last year?

With a record warm start to spring 2026 in much of the U.S., the answer is a teary-eyed “yes.”

More than 1 in 4 U.S. adults suffer from seasonal allergies. That number is expected to increase as climate change results in longer and more intense pollen seasons.

When someone talks about having allergies, they are referring to a condition called allergic rhinitis or allergic conjunctivitis – inflammation of the nose or eyes related to allergen exposure. This results in itchy, watery eyes, runny nose, sneezing, congestion and nasal passage itching. They show up when allergens are in the air, during spring, summer and fall.

The big driver of seasonal allergies is a protein in pollen. Pollen is the male reproductive material that plants release to spread their species.

Those pollen proteins become problems when the immune system develops an allergic antibody known as IgE to these proteins. When several IgE molecules bind to the allergen when it lands on the tissues of the eye or nasal passages, the cells release molecules such as histamine, prostaglandins and leukotrienes. These molecules interact with blood vessels and nerves to........

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