What causes sinusitis?

The sinuses are air-filled spaces around the nose and eyes. A common cold can swell their lining and prevent mucus from draining. Allergic rhinitis can cause similar swelling when the nose reacts to allergens. Trapped mucus may create pressure, a blocked nose, facial tenderness, reduced smell, or a thick nasal discharge. Many episodes begin with a viral illness; bacteria may be involved in some longer-lasting or worsening cases. Dental problems, nasal polyps, or structural narrowing can also make drainage difficult.

Rest, drink fluids, and use a saline nasal rinse or spray if it is suitable for you. A pharmacist or clinician can advise on pain relief and whether a nasal treatment may help. Avoid smoke and other irritants. If allergies are a trigger, reducing exposure and following an allergy plan may reduce repeated blockage. Seek advice when symptoms are severe, persist, or improve and then become worse again; antibiotics are not useful for every episode.

Arrange prompt review for swelling around an eye, severe one-sided facial pain, a severe headache, vision changes, or a high fever with marked illness. Seek urgent help for confusion, a stiff neck, or trouble breathing. Repeated episodes or symptoms mainly on one side deserve assessment for an underlying nasal or dental problem.

Is this more consistent with a cold, allergy, or sinusitis? Could a dental issue or nasal blockage be contributing? Which treatments are suitable for me? What changes should prompt a faster review?