An allergic reaction to pollen, causing symptoms such as sneezing, runny nose, and itchy eyes (commonly called seasonal allergic rhinitis or hay fever).
毎年春になると花粉症がひどくなる。
Every spring my hay fever gets worse.
花粉症のせいで夜よく眠れないことがある。
Because of hay fever, sometimes I can't sleep well at night.
薬局で花粉症の薬を買った。
I bought medicine for hay fever at the pharmacy.