Sinus Infection Won’t Go Away After Antibiotics: Causes and Next Steps

Sinus Infection Won’t Go Away After Antibiotics: Causes and Next Steps

Finishing an antibiotic and still feeling congested, full, or pressure-like can be discouraging—especially if you expected quick relief. If your sinus infection won’t go away after antibiotics, it doesn’t necessarily mean something is wrong with you or that you automatically need a stronger prescription.

One key reason: antibiotics only treat bacterial infections and are ineffective against viral infections or non-infectious inflammation. A useful way to think about it: antibiotics can target bacteria, but they can’t unclog swollen drainage pathways or calm an irritated sinus lining. That’s why lingering symptoms are common—and there are clear, evidence-based next steps to help you figure out what’s going on and what to do next (Mayo Clinic).

In this guide, you’ll learn:

- What’s normal (and not normal) after finishing antibiotics

- Common reasons sinus symptoms persist

- When an ENT evaluation can be helpful and what testing may be used

- Treatments that often help beyond antibiotics, including anti-inflammatory and procedural options (Mayo Clinic)

You can also read more about viral vs bacterial sinus infections here: https://sleepandsinuscenters.com/blog/viral-vs-bacterial-sinus-infections-key-differences

When Is It "Normal" to Still Feel Sick After Antibiotics?

Typical recovery timeline (acute sinusitis)

Even when the main illness is improving, it’s common for mild congestion, facial pressure, or a lingering cough (often from postnasal drip) to hang on for a few days. Many people notice the last symptom is either the cough at night or the lingering stuffiness in the morning.

What matters most is the trend: symptoms should gradually improve, not keep escalating. A simple check-in question clinicians often ask is, “Compared to three days ago, are you clearly moving in the right direction?” If the answer is yes—even if you’re not 100%—that can be reassuring.

Red flags that suggest the problem isn’t resolving

If symptoms persist or intensify, it may be time—together with your clinician—to re-check the diagnosis rather than repeating the same approach. Some patterns that raise concern include:

- Symptoms that continue more than 10–14 days after completing antibiotics

- Worsening after initial improvement (sometimes called double worsening)

- Severe facial pain, high fever, swelling around the eyes, vision changes, severe headache, confusion, or other signs that may need urgent evaluation (Mayo Clinic)

If you’re experiencing eye swelling, vision changes, or severe headache symptoms, treat that as a don’t wait it out moment—seek urgent evaluation.

When it becomes chronic sinusitis

Sinus symptoms lasting 12 weeks or more may meet criteria for chronic sinusitis. Chronic sinusitis is often less about an ongoing active infection and more about persistent inflammation and blocked drainage pathways (Mayo Clinic).

Another helpful analogy: acute sinusitis is like a sudden traffic jam. Chronic sinusitis is more like ongoing construction that keeps lanes narrowed—drainage and airflow can’t normalize, so symptoms keep returning or never fully clear.

Learn more about chronic sinusitis here: https://sleepandsinuscenters.com/chronic-sinusitis

Bottom line: improvement over time is reassuring; persistent, worsening, or 12-week symptoms warrant a closer look with a clinician.

Symptoms of a Sinus Infection That May Persist (And What They Can Mean)

Common lingering symptoms

Persistent sinus symptoms don’t always mean bacteria are still present. Common symptoms people may continue to feel include:

- Nasal congestion/stuffy nose

- Facial pressure, fullness, or heaviness

- Postnasal drip and cough (often worse at night)

- Thick nasal drainage (this can occur with infection or inflammation)

- Reduced sense of smell or taste

- Fatigue or brain fog (Mayo Clinic)

A common scenario: you finish antibiotics, your fever (if you had one) is gone, but you still feel blocked up and tired—especially in the mornings. That pattern often points toward inflammation and drainage issues rather than needing stronger antibiotics.

Quick myth-buster: Thick or colored mucus can be caused by inflammation or viral illness and does not necessarily indicate a bacterial infection requiring antibiotics.

Symptoms that suggest a different diagnosis

Some sinus symptoms overlap with other conditions. For example:

- Migraine or tension headaches can mimic sinus pressure

- Jaw or tooth pain can be related to sinus issues, but dental problems can also refer pain to the face

- Ear pressure/fullness may point to Eustachian tube dysfunction alongside nasal inflammation (Mayo Clinic)

These conditions can cause sinus-like symptoms but are separate diagnoses and require different treatments.

When symptoms don’t match the typical pattern of bacterial sinusitis, it’s another reason your sinus infection won’t go away after antibiotics—because the root cause may not be bacterial in the first place.

Key takeaway: lingering congestion, pressure, or cough often reflects inflammation or another condition—not ongoing bacteria.

Why Your Sinus Infection Won’t Go Away After Antibiotics (Most Common Causes)

The big takeaway: persistent symptoms often mean the main issue is not bacterial, or there’s an underlying trigger keeping inflammation going.

1) The infection was viral (antibiotics don’t treat viruses)

Many sinus infections start as a viral upper respiratory infection (a cold). Viruses can cause congestion, thick drainage, pressure, and postnasal drip—symptoms that feel very sinus-specific. Antibiotics don’t treat viruses, so it’s possible to finish antibiotics and still feel stuck because the illness was never bacterial.

A practical example: you may feel slightly better mid-course, then plateau—because the viral timeline and the body’s recovery process, not bacteria, is driving what you feel.

2) Ongoing inflammation (chronic sinusitis)

Chronic sinusitis is often driven by persistent swelling of the sinus lining, which blocks normal drainage and ventilation. When drainage pathways are narrowed, mucus can build up, creating a cycle of congestion and pressure. Chronic sinusitis can occur with or without nasal polyps (Mayo Clinic).

Clinicians often describe this as a swelling problem more than a germ problem. If swelling is the main issue, anti-inflammatory strategies frequently do more than additional antibiotics.

3) Allergies (seasonal or indoor)

Allergies can look a lot like infection:

- Nasal swelling and stuffiness

- Runny nose or postnasal drip

- Cough from drainage

- Facial pressure from congestion

If allergies aren’t addressed, symptoms can return quickly—making it feel like your sinus infection won’t go away after antibiotics, even when bacteria weren’t the issue. For many people, this shows up as predictable flare seasons or symptoms that worsen with dust, pets, or yard work.

If recurring congestion and postnasal drip are part of your pattern, this resource on allergy testing may help you plan next steps: https://sleepandsinuscenters.com/allergy-testing

4) Structural issues that block sinus drainage

Some people have anatomy that makes drainage more difficult, such as:

- Deviated septum

- Narrow sinus drainage pathways

- Turbinate enlargement

- Other structural variations that reduce ventilation

When airflow and drainage are limited, inflammation and sinus infection–like symptoms can be more frequent and harder to fully clear. In real life, that can look like: Every cold turns into a sinus issue, or I always feel blocked on one side.

5) Nasal polyps or chronic swelling inside the nose

Nasal polyps are soft, non-cancerous growths associated with chronic inflammation. They can physically block airflow and drainage and are often linked with reduced sense of smell (Mayo Clinic).

A common clue patients mention is: I can’t smell like I used to, especially if it’s persistent or keeps recurring.

6) Resistant bacteria or the wrong antibiotic (less common, but possible)

Although less common, sometimes bacteria may be resistant to the prescribed antibiotic, or other factors may prevent infection resolution. In those situations, clinicians may consider more targeted evaluation rather than simply extending or repeating treatment.

If you’re not improving, the next step is often not a longer course—it’s a better look at what’s actually happening inside the nose and sinuses.

In short: most lingering symptoms reflect inflammation, anatomy, or allergies—less often persistent bacteria.

Next Steps If You’re Not Better After Antibiotics

Step 1 — Re-check the diagnosis (don’t just repeat antibiotics)

When a sinus infection won’t go away after antibiotics, repeating antibiotics without revisiting the diagnosis may not help—and it can increase side effects and contribute to antibiotic resistance. Work with your clinician to clarify what’s driving your symptoms.

Helpful information to bring to a visit includes:

- When symptoms started

- Whether you improved, plateaued, or worsened

- What medications you tried (including nasal sprays, rinses, allergy meds)

- Any known triggers (seasonal allergies, dust exposure, smoke, recent viral illness)

If you can, note a few specifics (even in your phone): Worst symptom, time of day it’s worst, and what makes it better or worse. Those details often help narrow the cause quickly.

Step 2 — Make an appointment with an ENT specialist

An ENT evaluation can be useful when symptoms persist, recur, or don’t respond as expected. The goal is to identify whether this is more consistent with chronic sinusitis, polyps, allergy-driven inflammation, structural blockage, or another look-alike condition (Mayo Clinic).

Sleep and Sinus Centers of Georgia often sees patients who don’t need stronger antibiotics—they need a plan that targets inflammation and drainage.

Step 3 — Know what tests the ENT may use

Nasal endoscopy (in-office): A thin, lighted scope looks inside the nose to assess swelling, drainage, polyps, and areas that may be blocked or inflamed (Mayo Clinic).

Many patients are surprised by how practical this is: it gives real-time information about what’s swollen, what’s draining, and whether polyps or significant irritation are present.

CT scan of the sinuses: A sinus CT scan can show detailed anatomy and signs of chronic inflammation or blockage. It’s commonly used for chronic or recurrent symptoms, and it may be part of planning if a procedure is being considered (Mayo Clinic).

This can be especially helpful when symptoms and exam findings don’t fully match—or when anatomy may be contributing to repeated episodes.

Best next move: partner with an ENT to confirm the cause before repeating antibiotics.

Treatments Beyond Antibiotics (What Actually Helps Persistent Sinus Symptoms)

If you’re dealing with symptoms that persist after antibiotics, the most effective next step is often shifting from germ-killing to inflammation-reducing + drainage-improving strategies (Mayo Clinic).

At-home and OTC supportive care (often first-line)

- Saline irrigation/rinses: Helps rinse out mucus, irritants, and allergens and can improve nasal comfort (Mayo Clinic)

- Hydration and humidification (aim for comfortable—not overly damp—air)

- Warm compresses or steam for comfort

- Sleeping with your head slightly elevated to reduce nighttime congestion

Consistency matters here. For example, daily saline rinses during a flare can help the nose and sinuses clear buildup—like rinsing dust out of an air filter so air can move again.

Prescription anti-inflammatory treatments (common next step)

Depending on the cause, clinicians may discuss:

- Nasal corticosteroid sprays to reduce inflammation and swelling (Mayo Clinic)

- A short course of oral steroids in select situations (provider-guided)

- If allergies are contributing: targeted allergy medications may be part of the plan

If you’ve tried a nasal spray before and it didn’t work, it may still be worth revisiting technique, duration, and whether the medication choice matched your diagnosis—small adjustments can make a big difference.

Allergy management (when allergies are the driver)

When allergies keep the nose inflamed, treating the allergy can reduce the constant congestion cycle. Options may include:

- Identifying triggers (sometimes with testing)

- Environmental steps (dust/mold/pet dander/pollen strategies)

- Immunotherapy options in appropriate patients

Explore allergy testing here: https://sleepandsinuscenters.com/allergy-testing

Procedures and surgery (when drainage pathways are blocked or medical therapy fails)

If symptoms continue despite appropriate medical management—or if anatomy is significantly limiting drainage—procedures may be discussed.

Balloon sinuplasty (for selected patients)

Balloon sinuplasty is designed to widen drainage pathways and improve ventilation. Learn more about balloon sinuplasty here: https://sleepandsinuscenters.com/balloon-sinuplasty

Functional Endoscopic Sinus Surgery (FESS)

FESS is a procedure that can remove obstruction (such as polyps) and improve sinus drainage. It’s typically considered when chronic sinusitis does not respond to medical management (Mayo Clinic).

Most people improve by reducing inflammation, treating allergies, and improving drainage—procedures are reserved for the right anatomy and situations.

Lifestyle Tips to Prevent Future "Lingering Sinus Infections"

Reduce inflammation triggers

- Manage allergies early and consistently during your season

- Avoid smoke and strong fragrances when possible

- Address indoor triggers like dust and mold if they’re relevant for you

If you notice a pattern—like symptoms flaring after cleaning, travel, or seasonal pollen spikes—that’s useful information to bring to your clinician.

Improve sinus drainage habits

- Consider regular saline rinses during flare seasons

- Aim for a comfortable indoor humidity level; very dry air can irritate, while excessive humidity can worsen mold issues for some households

Know when to seek care sooner

If you repeatedly need antibiotics, symptoms keep returning, or a sinus infection won’t go away after antibiotics more than once, an evaluation can be more useful than ongoing trial-and-error.

Prevention hinges on minimizing triggers, supporting drainage, and seeking evaluation early when patterns repeat.

FAQs

Why do I still have sinus pressure after antibiotics?

Pressure can persist due to inflammation, allergies, blocked drainage, or a viral illness rather than a bacterial infection. Chronic sinusitis is also a possibility if symptoms are prolonged (Mayo Clinic).

Should I ask for a stronger antibiotic?

Not automatically. When symptoms persist, it’s often more helpful to confirm the diagnosis and look for underlying drivers (like inflammation, allergies, polyps, or structural blockage) rather than escalating antibiotics without additional evaluation.

How long is too long for sinus symptoms?

As a general guideline, ongoing symptoms more than 10–14 days after finishing antibiotics, or symptoms lasting 12 weeks or more overall, may suggest chronic sinusitis or another underlying cause (Mayo Clinic).

When should I see an ENT for a sinus infection?

If symptoms persist, recur frequently, don’t respond to treatment as expected, or include concerning features (like severe pain, swelling around the eyes, vision changes, or severe headache), an ENT evaluation may be appropriate (Mayo Clinic).

Will an ENT do a CT scan right away?

Often, the first step is history and exam (and sometimes nasal endoscopy). A CT scan may be used for chronic or recurrent symptoms or before considering procedures (Mayo Clinic).

Can allergies cause a sinus infection feeling?

Yes. Allergies can cause congestion, swelling, postnasal drip, cough, and pressure that mimic infection and can prolong symptoms (Mayo Clinic).

If in doubt, a targeted evaluation is the quickest path to the right treatment.

Conclusion: What to Do If Symptoms Linger

When a sinus infection won’t go away after antibiotics, the most common explanations are viral illness, chronic inflammation, allergies, polyps, or structural blockage—not simply needing more antibiotics. The next best step is usually a targeted evaluation so treatment matches the real cause.

If your symptoms are lingering or frequently returning, consider scheduling an evaluation with Sleep and Sinus Centers of Georgia to review your history and discuss diagnostic and treatment options. To book an appointment, visit https://www.sleepandsinuscenters.com/ and choose the location and appointment option that fits your needs.

Related resources:

- Chronic sinusitis: https://sleepandsinuscenters.com/chronic-sinusitis

- Allergy testing: https://sleepandsinuscenters.com/allergy-testing

- Balloon sinuplasty: https://sleepandsinuscenters.com/balloon-sinuplasty

Source: Mayo Clinic, chronic sinusitis diagnosis and treatment overview: https://www.mayoclinic.org/diseases-conditions/chronic-sinusitis/diagnosis-treatment/drc-20351667

This article is for educational purposes only and is not medical advice. Please consult a qualified healthcare provider for diagnosis and treatment.