Sinusitis Explained: Causes, Symptoms and Relief

What is sinusitis?

Sinusitis is inflammation of the sinuses — the air-filled spaces behind the cheeks, forehead and nose. When the lining of these spaces becomes swollen, mucus cannot drain properly, leading to pressure, pain and congestion. It is a very common condition and often follows a cold.

Sinusitis is usually described as acute when it lasts a few weeks and chronic when symptoms persist for many weeks or keep returning.

What causes it?

Most cases of acute sinusitis are triggered by viral infections, such as the common cold. Other contributors include:

• Allergies, such as hay fever
• Nasal polyps or a deviated septum
• Bacterial infection, which is less common and usually develops after a viral illness
• Irritants such as smoke or pollution

Because the majority of cases are viral, antibiotics are usually unnecessary and ineffective. Antibiotics do not treat viruses, and using them inappropriately fuels resistance.

Recognising the symptoms

Typical symptoms include:

• Pain, pressure or tenderness around the cheeks, eyes or forehead
• A blocked or runny nose
• Reduced sense of smell
• Thick, discoloured nasal mucus
• Headache and a feeling of fullness in the face
• Sometimes a cough or mild fever

Symptoms often worsen when bending forward. Most cases improve within two to three weeks.

How sinusitis is treated

For most people, sinusitis clears on its own with supportive care. Helpful measures include:

• Rest and plenty of fluids
• Steam inhalation to loosen mucus
• Saline nasal rinses or sprays
• Warm compresses over the face
• Over-the-counter pain relief such as paracetamol if suitable
• Decongestant sprays for short-term use only, as advised by a pharmacist

A doctor may consider antibiotics only when a bacterial infection is strongly suspected — for example, if severe symptoms persist or worsen after about ten days. In those situations, finishing the full prescribed course is essential, and you should always declare any penicillin or sulfa allergy. You can read about common options in our antibiotics range and our Amoxicillin guide.

Why antibiotics are not the default

Professionals are cautious about prescribing antibiotics for sinusitis because most cases are viral and resolve naturally. Unnecessary antibiotics expose you to side effects and contribute to a wider loss of effectiveness. Our guide to antibiotic resistance explained explains why this restraint protects everyone.

When to see a doctor

Seek medical advice if symptoms last longer than two to three weeks, are severe or keep coming back, or if you develop swelling or redness around the eyes, a severe headache, a stiff neck, vision changes or confusion. These rarer warning signs need prompt assessment.

Key takeaways

Sinusitis is usually a self-limiting, viral condition that responds well to rest and simple symptom relief. Antibiotics are reserved for the minority of cases caused by bacteria, so following professional advice helps you recover comfortably and use medicines wisely.

General information only — not medical advice. Always read the patient information leaflet and consult a doctor or pharmacist before starting any medication.