Steroid nasal sprays are medicines that are sprayed into the nose, to prevent and treat allergy symptoms of the nose such as stuffy or runny nose, itching, and sneezing. These usually occur with hay fever (also called allergic rhinitis ). Steroid nasal sprays are also used to treat certain growths in the nose called nasal polyps . They work by reducing swelling (inflammation) and mucus in the nose. Because the medicine mainly works in your nostrils, it has very little effect anywhere else in your body. People with hay fever only need to use them for a few months of the year, during the hay fever season, but others may need to use them long-term.