Mometasone furoate nasal spray is a therapeutic drug for respiratory diseases, mainly for the treatment and prevention of allergic rhinitis. The side effects are first of all local adverse reactions, such as possible nasal bleeding or nasal irritation or burning sensation, the nasal bleeding is self-limiting and at the same time relatively mild. Secondly, there are other local or systemic adverse reactions, such as headache, pharyngitis, and in rare cases, allergic reactions or angioedema. The safety of this drug is still relatively high, and most patients can tolerate it. However, patients should consult their doctor or pharmacist if they experience any side effects during the course of use.