Sinusitis in London: When Will It Clear, and Do I Need Antibiotics?

Sinus pressure can make a normal working day hard. Most acute sinusitis follows a cold and settles without an antibiotic. The key questions are how long symptoms have lasted, whether they are worsening, and whether a complication is possible. A good assessment should give you a plan for relief and a clear reason for any prescription.

What does sinusitis feel like?

A blocked or runny nose, facial pain or pressure, reduced smell and sometimes a headache can follow a cold. Yellow or green mucus alone does not prove you need an antibiotic. A dental problem can also cause one-sided facial pain. NICE says acute sinusitis usually lasts two to three weeks; the NHS says it often clears on its own within four weeks. These are guides, not a reason to ignore rapid deterioration.

When are antibiotics useful?

NICE recommends no antibiotic when symptoms have lasted about ten days or less. At ten days or more without improvement, a clinician may still recommend no antibiotic or offer a back-up prescription. Antibiotics make little difference to the duration or chance of improvement for most people, while nausea and diarrhoea are possible. A clinician weighs the whole picture and your risk of complications, rather than prescribing solely because mucus is coloured. An immediate antibiotic may be needed if you are systemically very unwell or at high risk of complications.

What can help while I recover?

Rest and drink enough fluid. Paracetamol or ibuprofen may help pain or fever if they are safe for you. A pharmacist can advise on nasal treatments and whether they fit your health and medicines. NICE says a clinician may consider a high-dose nasal corticosteroid for 14 days when symptoms have lasted ten days or more, but it is not expected to shorten the illness and may have adverse effects. Discuss it rather than starting a high-dose course on your own. Do not use leftover antibiotics.

When should I seek urgent help?

Seek urgent medical assessment if you become very unwell or symptoms worsen rapidly or significantly. Swelling around the eye, double vision, a displaced eye or reduced vision may mean an orbital complication. A severe frontal headache, forehead swelling, signs of meningitis or new neurological symptoms also need urgent assessment. NICE advises hospital referral for these features. Do not wait for a routine private appointment in this situation.

What will a GP check?

The GP asks about symptom duration, fever, pain, nasal symptoms and what happened after the cold. They can examine the nose, face and, when appropriate, teeth and eyes, consider an alternative cause, and explain whether self-care, a back-up prescription, immediate treatment or referral is justified. If symptoms have not improved after three weeks of self-care, or keep returning, arrange assessment.

What does an appointment cost?

The Online GP lists a same-day phone consultation at £59 and an in-person Marylebone GP appointment at £220. A phone call can help triage a familiar, mild illness. An in-person examination is more useful if the diagnosis is uncertain, one-sided pain raises a dental question, or symptoms are worsening. Any separate tests or treatment should be discussed before they are arranged.

Telephone GP: https://www.theonlinegp.com/services-store/p/same-day-telephone-gp

In-person GP: https://www.theonlinegp.com/services-store/p/same-day-urgent-in-person

If you are unsure which appointment fits, contact the team: https://www.theonlinegp.com/contact

Frequently asked questions

Does green mucus mean a bacterial infection? No. Colour alone does not establish the cause or justify an antibiotic; duration, severity and the examination matter.

How long can sinusitis last? NICE describes a usual course of two to three weeks; NHS advice says it often clears by four weeks. Seek review if not better after three weeks of self-care or if worsening.

Can a GP prescribe antibiotics for sinusitis? Yes, when indicated. NICE generally advises against them in the first ten days and allows a no-antibiotic or back-up approach later in uncomplicated cases.

When is sinus pain an emergency? Eye swelling, double vision, reduced sight, severe frontal headache, forehead swelling, meningitis signs or neurological symptoms need urgent assessment.

Sources: NICE acute sinusitis recommendations https://www.nice.org.uk/guidance/ng79/chapter/recommendations

NHS sinusitis guidance https://www.nhs.uk/conditions/sinusitis-sinus-infection/

General information, not a personal diagnosis. Written and reviewed by the clinical team at The Wellness. Updated September 2026.