A Sinus Infection That Will Not Go Away

Short answer

• A sinus infection that will not go away is usually not one stubborn infection that needs a stronger version of the same treatment. More often, the timeline is pointing to something else: a viral illness that is still running its course, ongoing inflammation rather than a bacterial infection, a blocked drainage pathway, uncontrolled allergies, nasal polyps, a dental problem near a cheek sinus, or congestion that keeps rebounding from a decongestant spray. Clinicians read the pattern in stages. Symptoms that are improving within about 10 days are usually viral. Symptoms that last more than 10 days without improving, that are severe for several days, or that improve and then worsen again are more likely to need a clinician visit. Symptoms lasting 12 weeks or longer fit the definition of chronic sinusitis, which is a different condition from a single acute infection and usually needs an in person evaluation, often with an ear, nose and throat specialist. This article is general information only. It is not a diagnosis or a treatment plan for an individual, and it cannot tell you whether your own symptoms are viral, bacterial or chronic. What it can do is explain how clinicians use time and pattern to sort these problems, name the warning signs that need urgent care, and describe what an examination may look for when symptoms keep returning.

Red Flags That Need Care Right Away

Most sinus symptoms are uncomfortable rather than dangerous. A small number of signs change that picture, because an infection near the sinuses can, rarely, spread toward the eye or the tissues around the brain. Mayo Clinic advises seeking care right away for symptoms that could signal a serious infection. Do not wait for a routine appointment if sinus symptoms come with any of the following:

• Swelling or redness around the eyes
• Double vision, reduced vision or any other vision change
• Swelling of the forehead
• A severe or unusual headache
• Confusion
• A stiff neck
• Fever with severe illness, or symptoms that are rapidly getting worse

If any of these appear, urgent care comes before any discussion of timelines, antibiotics or procedures in the rest of this article. People with a weakened immune system should also seek advice earlier rather than later, because the usual watch and wait thresholds may not apply in the same way. When in doubt about a severe symptom, get urgent medical advice rather than trying to match your symptoms to a list at home.

How Clinicians Read the Timeline

Time is the single most useful piece of information in a lingering sinus problem, which is why clinicians ask when symptoms started before they ask almost anything else. MedlinePlus, the patient information service of the US National Library of Medicine, divides sinusitis by duration. The American Academy of Otolaryngology, Head and Neck Surgery takes a similar approach in its adult sinusitis guideline, and adds a requirement that chronic disease be confirmed by examination or imaging, not by symptoms alone.

Pattern	Time frame	What it usually means
Acute sinusitis	Up to 4 weeks	A short term inflammation, most often following a viral cold
Subacute sinusitis	4 to 12 weeks	Symptoms that have outlasted an acute episode but have not yet reached the chronic threshold
Chronic sinusitis	12 weeks or longer	Ongoing inflammation that needs evaluation and objective confirmation
Recurrent sinusitis	Several separate attacks within a year	Repeated acute episodes, with clearer periods in between

Inside the acute window, the pattern matters as much as the count of days. The Centers for Disease Control and Prevention summarizes the patterns clinicians use to suspect a bacterial infection: symptoms lasting 10 days or more without improvement; severe symptoms, such as a fever of 102 degrees Fahrenheit or higher with nasal discharge and facial pain, lasting three to four days; or symptoms that improve after four to seven days and then worsen again. That last pattern is sometimes called double worsening. None of these patterns proves a bacterial infection on its own, and mucus color alone does not prove one either. Green or yellow mucus can occur as the immune system responds to a viral illness.

Chronic sinusitis is stricter than simply feeling unwell for a long time. In the Academy guideline, it means 12 weeks or longer of two or more features, such as colored nasal drainage, nasal obstruction, facial pain, pressure or fullness, or a decreased sense of smell, together with documented inflammation. That documentation can come from nasal endoscopy, which can show colored mucus, swelling or polyps, or from imaging showing inflammation of the sinuses. This is why a clinician may not accept a self diagnosis of chronic sinusitis based on duration alone, and why an examination is a real diagnostic step rather than a formality.

A simple calendar note helps at any appointment. Write down when symptoms started, whether they improved, when they turned again, any fever and how long it lasted, and what you have already tried. That record is far more reliable than memory after weeks of poor sleep. Our companion guide to postnasal drip that is more than allergies shows how the same kind of timeline helps sort drainage that comes from the nose and sinuses from drainage driven mainly by allergy.

The Symptoms That Tend to Linger

The symptoms of acute and chronic sinusitis overlap, which is part of why they are so often confused. Mayo Clinic lists the common features of chronic sinusitis as thick, discolored mucus from the nose, mucus draining down the back of the throat, a blocked or stuffy nose that makes breathing through the nose hard, and pain, tenderness and swelling around the eyes, cheeks, nose or forehead, together with a reduced sense of smell and taste. Other features can include ear pain, headache, aching in the teeth, cough, sore throat, bad breath and tiredness.

Two differences help separate a long acute illness from chronic disease. First, fever is not common in chronic sinusitis, although it can be part of an acute infection. Second, chronic symptoms persist even with treatment, rather than rising and falling with a single cold. A person can also have several bouts of acute sinusitis before chronic sinusitis develops, so a history of repeated infections is relevant information for a clinician, not just background detail.

Pressure is the symptom many people judge their recovery by, and it can be misleading on its own. Facial pain or pressure without colored nasal drainage is not enough, by itself, to establish a sinus infection diagnosis in the Academy guideline. Pressure can rise and fall with congestion and how swollen the nasal lining is that day. Our guide to how to relieve sinus pressure covers the general measures people use for that symptom and the point at which pressure itself becomes a reason to see an ear, nose and throat specialist. For a wider picture of the system the sinuses drain into, see our explainer on how the breathing system works.

Why Symptoms Persist: The Main Groups of Causes

A viral illness that has not finished yet

Most sinus infections begin as viral colds. The CDC review of the evidence puts the share of sinus infections caused by viruses at 90 to 98 percent. Viral inflammation swells the lining of the nose and sinuses, traps mucus and produces congestion, facial pressure and discolored discharge that can look exactly like a bacterial infection feels. Antibiotics do not treat viruses, so a course of antibiotics given during a viral illness can appear to fail when in fact there was never a bacterial target for it to act on. The lingering congestion after a cold is often this inflammation taking time to settle.

A bacterial pattern on top of a viral start

A smaller share of cases follow the bacterial patterns described above: no improvement after 10 days, severe symptoms for several days, or double worsening after an initial recovery. Even here, the decision belongs to the clinician who examines you. The same 10 day mark can also reflect slow viral recovery, allergy or a new cold arriving on top of the old one. That overlap is exactly why guidelines describe patterns rather than a single test a patient can apply at home.

Chronic inflammation rather than a single infection

In chronic sinusitis, the central problem is ongoing inflammation of the sinus lining. Mayo Clinic notes that infection, nasal polyps and swelling of the lining can all be part of the condition, and that the underlying cause is often not known. Inflamed tissue keeps the drainage openings narrow, mucus does not clear well, and symptoms return or never fully leave. Repeated short courses aimed at a single infection may bring brief relief without changing the inflammation underneath, which is one common reason people feel stuck in a cycle.

A blocked drainage pathway

The sinuses drain through small openings, and anything that narrows those openings can keep symptoms going. A deviated nasal septum, the wall between the nostrils sitting off center, can restrict or block sinus passages. Nasal polyps, soft noncancerous growths on the lining of the nose or sinuses, can also block passages. Cleveland Clinic lists a deviated septum and nasal polyps among the causes its clinicians test for when sinusitis keeps recurring. Medication can reduce swelling, but it cannot straighten a septum or remove a large polyp, which is why an examination matters when the same side of the nose is always blocked.

Allergies and other ongoing irritation

Allergies can keep the nasal and sinus lining inflamed between infections. Mayo Clinic advises people with chronic sinusitis to work with their care provider to keep allergies under control and to avoid cigarette smoke and polluted air, which irritate the nasal passages. If every infection is treated but the allergy driving the swelling is not addressed, symptoms tend to return. Asthma and other long term airway conditions can also travel with chronic sinus disease, and the Academy guideline advises clinicians to assess people with chronic or recurrent sinusitis for coexisting conditions that may affect management. A sinus problem that arrives with a familiar seasonal pattern, itchy eyes or sneezing fits may therefore need allergy care alongside sinus care. Readers sorting out a respiratory virus from sinus symptoms may also find our guide to what flu B is useful, since flu and colds are the usual starting point for acute sinus inflammation.

A dental source near the cheek sinuses

Not every sinus like problem starts in the sinuses. The roots of the upper teeth sit close to the maxillary sinuses, the sinuses behind the cheeks. Mayo Clinic lists a dental infection among the risk factors for chronic sinusitis. A tooth problem can produce cheek pain, pressure and an ache in the upper teeth that feels like sinus pain, and sinus treatment will not resolve a problem whose source is a tooth. If sinus symptoms sit alongside tooth pain, swelling or fever, tell the clinician about the dental symptoms as well, so that both possible sources can be examined. You may need dental care, medical care, or both, and the order matters.

Immune and other medical factors

Less commonly, conditions that affect the immune system or the way mucus is cleared can make sinus disease recur or persist. The Academy guideline names immunocompromise and conditions affecting mucus clearance among the coexisting problems clinicians should consider in chronic or recurrent cases. This is not a reason to assume a serious underlying condition, which is uncommon. It is a reason to mention your full medical history, including immune problems, cystic fibrosis, asthma and medicines that affect immunity, when you are seen for sinus symptoms that will not settle.

Rebound congestion from decongestant sprays

One cause is easy to miss because it feels like the original illness. Nonprescription decongestant nasal sprays can, when used for more than three or four days, cause congestion that is worse once the spray wears off. Mayo Clinic describes this rebound effect and the spiral that follows: the person thinks the cold is getting worse, uses more spray, and ends up with more congestion and more spray use. Steroid nasal sprays work differently and do not carry this same rebound pattern, but the two types are often confused. If your congestion reliably surges as each spray dose fades, raise the spray habit itself at your appointment rather than only reporting the congestion. Do not stop or change a medicine you were told to use without advice, but do bring the packaging so the clinician can see exactly what you have been using and for how long.

When the source is not the sinuses at all

Constant nasal running and congestion without facial pressure may reflect rhinitis, inflammation of the nasal lining rather than the sinuses, which has its own causes and its own approach. Ear pressure can also overlap with sinus congestion, because the ears, nose and throat share connected passages; our sibling guide on why ears pop when you swallow explains that connection. The practical point is the same in each case: a symptom that sits in the face is not automatically a sinus infection, and repeating sinus treatment for a non sinus problem is a common route to feeling that nothing works.

Loss of Smell: What It Does and Does Not Prove

A reduced sense of smell is one of the defining features of chronic sinusitis, and for many people it is the symptom that worries them most. Swelling and polyps can stop odors from reaching the smell receptors high in the nose, and that kind of loss often improves as inflammation settles. Reduced smell and taste are listed together in the Mayo Clinic symptom picture because flavor depends heavily on smell.

Smell loss alone, though, does not diagnose the cause. It does not prove a bacterial infection, and it does not by itself prove chronic sinusitis either, since a simple cold can dull smell for days. It deserves prompt evaluation when it is one sided, sudden, or paired with other neurological symptoms, and it is worth raising at any appointment when it lasts beyond the acute illness. In the Academy guideline, a decreased sense of smell counts as one of the features that, sustained for 12 weeks or longer alongside documented inflammation, supports a chronic diagnosis. In other words, smell loss is a useful clue inside a pattern, not a verdict on its own.

Why Antibiotics May Not Be Helping

If antibiotics have not cleared your symptoms, there are several possible explanations, and most of them do not mean the medicine was too weak. The cause may be viral, in which case antibiotics have no target. The problem may be chronic inflammation rather than an active bacterial infection. A structural blockage, a polyp, an untreated allergy or a dental source may be keeping the cycle going regardless of medication. Or the spray habit described above may be recreating congestion between doses.

Guidelines are deliberately cautious here. Unnecessary antibiotics carry real costs, including side effects, allergic reactions and antibiotic resistance, which the CDC highlights as a central reason for careful prescribing. For chronic sinusitis, antibiotics are not a routine answer to ongoing symptoms; clinicians reserve them for situations where the history and examination support a bacterial infection, such as an acute flare with clear bacterial features. This article does not name a specific antibiotic, dose or course length for you, because that choice depends on examination findings, allergy history, other medicines and local resistance patterns. Never use leftover antibiotics or someone else’s prescription, and do not start, stop or change a prescribed medicine without professional guidance.

Watchful waiting is a legitimate part of this picture for mild, uncomplicated symptoms. It means supporting recovery, watching the pattern, and seeking care if symptoms pass the thresholds above or worsen. The NHS notes that sinusitis usually clears up on its own within four weeks and that antibiotics are rarely needed because the cause is usually viral. Watchful waiting only works as a plan if you know your threshold in advance. Waiting without a threshold is not a plan; it is delay.

General Measures While You Wait

For mild symptoms, general supportive measures can make the waiting period more comfortable while the lining settles. The NHS lists the usual self care steps for mild sinusitis: getting plenty of rest, drinking plenty of fluids, taking pain relief that is suitable for you, avoiding things that trigger your allergies, not smoking, and cleaning the nose with a salt water solution. Saline sprays and rinses are widely used to help clear mucus and keep the nasal lining moist, and steroid nasal sprays or drops may be recommended by a pharmacist or clinician to reduce swelling, sometimes over a period of months in chronic cases.

Follow product instructions and any advice you have been given personally, and check with a pharmacist if you are unsure whether a product is suitable for you, your child or your other medicines. If you use a rinse device, follow the manufacturer’s and clinician’s safety instructions for the water and cleaning; do not improvise a recipe or reuse solution. Treat any product that promises to cure chronic sinusitis, shrink polyps or clear a blocked sinus overnight with caution. A brand name does not prove a product will help, and no general article can tell you which product, if any, fits your situation.

What a Clinician or ENT Examination May Add

A routine visit can treat the symptoms in front of it. An evaluation for persistent symptoms is designed to answer a different question: why do they keep returning? Cleveland Clinic describes the first specialist visit as starting with detailed questions about what symptoms you have noticed, how long they have lasted, whether they have worsened and whether anything new has appeared, followed by a physical examination and tests to rule out other conditions.

Depending on your history and examination, those tests may include:

• Nasal endoscopy, a thin camera examination passed through the nose that shows the drainage pathways directly and can reveal swelling, colored mucus or polyps
• A CT scan of the sinuses, which maps the anatomy, shows inflammation and blockages that endoscopy cannot reach, and is used to confirm chronic disease and plan any procedure
• Allergy testing, where allergies are suspected of driving inflammation
• In selected cases, a sample or culture, imaging of the teeth, or referral to a dentist, allergist or another specialist

The Academy guideline is clear that chronic sinusitis should be objectively confirmed, by anterior rhinoscopy, nasal endoscopy or CT, rather than diagnosed from symptoms alone. The NHS similarly describes referral to an ear, nose and throat specialist when sinusitis is still present after three months of treatment, when it keeps returning, or when symptoms affect only one side of the face. One sided symptoms deserve particular attention, because they raise the possibility of a local cause, such as a dental problem or a growth, that a general sinus treatment would miss.

Treatment in General Terms: From Medical Care to Procedures

Most plans start with medical care aimed at the cause the examination found: reducing inflammation, helping mucus drain, treating a bacterial infection only when the pattern supports one, and managing allergies where they contribute. Cleveland Clinic notes that its clinicians usually have patients try medical treatments such as nasal irrigation or steroid sprays before talking about surgery, and that care plans differ because no two people experience chronic sinusitis in the same way.

Procedures enter the discussion when medical care is not enough and imaging and examination show a target for them. Functional endoscopic sinus surgery, usually shortened to FESS, is carried out through the nostrils and widens the sinuses by removing blocked tissue; the NHS describes it as the standard operation for chronic sinusitis. In selected cases a surgeon may instead inflate a tiny balloon in a blocked sinus opening to widen it, then remove the balloon, an approach called balloon sinuplasty. A deviated septum may be straightened by its own procedure. None of these fits everyone. Balloon widening, for example, does not remove polyps, and disease in several sinuses or with extensive polyps may be better served by endoscopic surgery. Which option, if any, fits depends on your anatomy, whether polyps are present and which sinuses are involved, which is why examination and imaging come first and why a responsible clinician will not promise an outcome in advance.

Preparing for an Appointment About Lingering Symptoms

You can make a persistent sinus appointment far more productive with a short written record. Bring the calendar of symptoms described earlier, a list of everything you have tried (including sprays, rinses and any antibiotics, with roughly how long you used each), your allergy history, any asthma or immune conditions, recent dental pain or dental work, and whether symptoms favor one side. Mention smell loss, fever patterns and any red flag symptoms you have had, even if they have since settled.

State your goal plainly too. Recurrent disease is assessed differently from one long episode, and the timeline you bring often moves the conversation from repeating a prescription to examining for a cause.

Frequently Asked Questions

How long is too long for a sinus infection?

See a clinician if symptoms last more than 10 days without improving, if they improve and then worsen, or if severe symptoms last several days. Symptoms lasting 12 weeks or longer meet the time definition of chronic sinusitis and should be evaluated in person, usually with objective confirmation by examination or imaging.

Why did antibiotics not clear my sinus infection?

The most common reasons are that the illness was viral, that the underlying problem is chronic inflammation rather than a bacterial infection, or that something else is keeping symptoms going, such as a deviated septum, nasal polyps, uncontrolled allergies, a dental source or rebound congestion from a decongestant spray. Antibiotics do not correct any of those. A clinician who examines you can sort out which explanation fits.

Will a sinus infection go away on its own?

Many will. Most acute sinus infections are viral, and the NHS notes that sinusitis usually clears up on its own within four weeks. Supportive care and watchful waiting are reasonable for mild symptoms, provided you seek care if you pass the 10 day threshold without improving, worsen after improving, develop a high or prolonged fever, or notice any red flag symptom.

Do I need a CT scan for chronic sinusitis?

Not everyone does. A CT scan is often used to confirm chronic sinusitis, map the anatomy and plan a procedure, but the decision follows your examination and history. Nasal endoscopy can sometimes provide the objective evidence needed. Your clinician will explain why imaging is, or is not, being recommended in your case.

Should I see an ENT specialist or an allergist?

Start with your usual clinician, who can assess the timeline and refer onward. An ENT specialist can examine the sinuses directly, look for polyps or structural blockage and discuss procedures. An allergist becomes important when allergies appear to be driving the inflammation. Some people need both, and the order usually begins with the clinician who can examine the sinuses.

Is balloon sinuplasty right for everyone with chronic sinusitis?

No. It suits certain patterns of blocked sinus openings, and it does not remove polyps. Extensive disease or polyps in several areas may be better treated with endoscopic sinus surgery, and many people need no procedure at all. Examination and imaging decide which option, if any, fits.

Can loss of smell mean my sinus problem is chronic?

It can be part of the picture, since reduced smell is one of the features clinicians count toward a chronic sinusitis diagnosis when it lasts 12 weeks or longer alongside other symptoms and documented inflammation. On its own it proves nothing, because a cold can dull smell temporarily. Persistent, one sided or sudden smell loss should be evaluated promptly.

Sources & references

• Centers for Disease Control and Prevention, Diagnosing and Treating Acute Bacterial Rhinosinusitis: New Guidelines from the Infectious Diseases Society of America. https://www.cdc.gov/patient-safety/stories/diagnose-treat-acute-bacterial-rhinosinusitis-new-guidance.html
• Mayo Clinic, Chronic Sinusitis: Symptoms and Causes. https://www.mayoclinic.org/diseases-conditions/chronic-sinusitis/symptoms-causes/syc-20351661?p=1
• Mayo Clinic, Mayo Clinic Q and A: Decongestants Can Sometimes Cause More Harm Than Good. https://newsnetwork.mayoclinic.org/discussion/mayo-clinic-q-and-a-decongestants-can-sometimes-cause-more-harm-than-good/
• Cleveland Clinic, Chronic Sinusitis Care. https://my.clevelandclinic.org/services/chronic-sinusitis-treatment
• NHS, Sinusitis (Sinus Infection). https://www.nhs.uk/conditions/sinusitis-sinus-infection/
• MedlinePlus, US National Library of Medicine, Sinusitis. https://medlineplus.gov/sinusitis.html?ref=lavieensante.com
• American Academy of Otolaryngology, Head and Neck Surgery Foundation, Adult Sinusitis Clinical Practice Guideline Update (2025), Guideline Central bundle. https://eguideline.guidelinecentral.com/i/1538079-adult-sinusitis-2025-update/2