Chronic sinusitis generally does not cause cancer, but if chronic sinusitis persists for a long time, it may increase the probability of sinus cancer. Chronic sinusitis is a chronic inflammation that occurs in the mucous membrane of sinuses. Most patients have a better prognosis after active treatment and generally do not cause cancer, but those who do not receive treatment may increase the risk of sinus cancer due to the long-term stimulation of the mucous membrane of sinuses by the inflammation. Sinus cancer is a malignant tumor that occurs in sinus, and its etiology is still unclear, which may be related to long-term chronic inflammation stimulation, malignant transformation of benign tumors (e.g. inverted papilloma, etc.), trauma, long-term exposure to carcinogenic substances, etc. Clinical manifestations mainly include nosebleed, olfactory obstruction, nasal congestion, protruding eyes, overflow of tears, etc. In serious cases, facial bulge and asymmetric face can occur due to tumor spreading. It is recommended that patients with chronic sinusitis should consult the doctor in time and follow the doctor’s instructions to avoid delaying their condition.