Overview
Sinusitis is inflammation of the mucous membrane lining the sinuses, the air-filled cavities in the skull around the nose. Acute sinusitis usually follows a cold and resolves within 4 weeks. Chronic sinusitis persists for more than 12 weeks. Most acute sinusitis is viral and does not require antibiotics.
How common is it?
About 1 in 7 adults in the UK experiences sinusitis each year, making it one of the most common conditions seen in primary care. Most cases are acute and resolve without treatment.
Causes and risk factors
Sinusitis occurs when the sinuses become blocked and infected — usually by viruses after a cold, or sometimes by bacteria, fungi, or allergies.
Common risk factors
- Viral upper respiratory infection (cold) — 90% of acute sinusitis cases
- Bacterial infection (secondary to viral): Streptococcus pneumoniae, Haemophilus influenzae
- Allergic rhinitis (chronic sinusitis)
- Nasal polyps
- Dental infection (upper teeth)
- Deviated nasal septum
- Smoking
- Immunosuppression
- Aspirin-exacerbated respiratory disease
- Swimming and diving (water entry into sinuses)
Symptoms
- Facial pain, pressure, or fullness, typically worse when bending forward
- Nasal congestion or blockage
- Thick discoloured nasal discharge
- Reduced or absent sense of smell (hyposmia)
- Headache, particularly over the forehead, cheeks, or around the eyes
- Tooth pain or jaw pain (maxillary sinusitis)
- Post-nasal drip causing cough and sore throat
- Fever (in bacterial sinusitis)
When to see a doctor
See a doctor for sinusitis lasting more than 10 days without improvement, worsening after initial improvement, severe headache unresponsive to analgesics, visual changes, swollen or red eye, stiff neck, or high fever. These may indicate rare but serious complications.
Diagnosis
Usually clinical. CT sinuses is the reference standard imaging but reserved for recurrent, severe, or complicated cases. Nasal endoscopy for chronic sinusitis assessment. Culture swabs in hospitalised or immunocompromised patients.
Treatments
Saline nasal irrigation
High-volume saline rinses (using a neti pot or nasal rinse bottle) are the most evidence-based non-pharmacological treatment. Reduce mucosal inflammation and clear secretions. Use daily for acute and chronic sinusitis.
Intranasal corticosteroid spray
Mometasone or fluticasone nasal spray reduces mucosal oedema in both acute and chronic sinusitis. First-line treatment for chronic sinusitis. Used daily, takes 1 to 2 weeks for full effect.
Antibiotics (selected cases)
Not recommended for routine acute sinusitis (90% viral). Reserve for bacterial sinusitis signs (fever above 38.5°C, persistent purulent discharge after 10 days, periorbital swelling): amoxicillin 500mg three times daily for 5 to 7 days.
Functional endoscopic sinus surgery (FESS)
For chronic sinusitis not responding to 12 weeks of medical treatment, or associated with nasal polyps or anatomical obstruction.
Self-care and lifestyle
- Use saline rinse morning and evening — most important self-care step
- Stay well hydrated to thin mucus secretions
- Inhale steam several times daily
- Avoid smoking and known allergen exposure
Prevention
Annual flu vaccination, managing allergic rhinitis, treating dental infections, and smoking cessation reduce sinusitis incidence and recurrence.