Sinusitis (Sinus Infection): Types, Diagnosis, and Remedies


Can allergies cause sinus infections?

Yes. While allergy symptoms can mimic a sinus infection without causing one, they can also create the ideal conditions—including congestion in facial and nasal cavities—for a sinus infection to develop. Speak to your doctor to determine if you have a sinus infection and need treatment.

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What Is A Sinus Infection (Sinusitis)?

A sinus infection is marked by inflammation in your facial and nasal cavities. Normally hollow, these cavities fill with mucus, creating the perfect environment for germs and bacteria to grow. Otherwise known as sinusitis, a sinus infection often mimics the symptoms of a standard cold.

When acute, this common condition can result in facial pain, fever, headaches, and pain in the upper jaw or teeth. Some experience blood in nasal discharge, as well. When these symptoms appear, it's important to see a doctor to figure out if the infection is bacterial and may need to be treated with medication.

Sinusitis can be short-lived, long-lasting, or even chronic. The symptoms can be minor and easily managed at home or chronic, with medical attention advised. With so many differences, understanding the type of sinus infection you have and what may have caused it will help you find the best treatment.

Let's dig deeper into some of the variables surrounding this common illness. It is important to know what causes a sinus infection and how to evaluate your symptoms in case they need medical attention.

Types of Sinus Infections

While you research or speak to your doctor about your condition, you may come across several terms used to describe a sinus infection. You may see the following descriptors, for example:

  • Minor: A sinus infection that starts with cold-like symptoms and resolves on its own, usually within a week, is described as minor.
  • Acute: Sinusitis that often starts suddenly and lasts from ten days to four weeks. An acute infection often means bacteria have had the chance to multiply.
  • Chronic: Ongoing sinus infections, which can last up to 12 weeks or longer, are often the result of an underlying issue—perhaps allergies or a structural issue such as nasal polyps or a deviated septum.

The type of infection you have will impact the symptoms you're experiencing, the way you will need to manage them, and whether or not you need to see a doctor.

Sinus Infection Symptoms

In its early stages, a sinus infection can be tricky to diagnose. If you experience a sore throat, runny nose, postnasal drip, and coughing, for example, you might wonder if they are symptoms of a cold or your seasonal allergies.

Over time, a sinus infection becomes more apparent. Here are a few clues to help distinguish between acute and chronic sinusitis.

Acute Sinusitis Symptoms

When a sinus infection has more severe symptoms, it is considered acute. Often, this occurs when sinusitis lasts for more than a week. It can be accompanied by fever, facial pain, blood in your nasal discharge, and pain in your upper jaw or teeth.

A sinus infection that becomes acute is often caused by an overgrowth of bacteria. When fluid fills your sinus cavities, it creates the perfect environment for a bacterial infection to develop. If you suspect your sinusitis has turned bacterial, reach out to your doctor immediately.

Chronic Sinusitis Symptoms

While chronic sinusitis is considered less severe than an acute sinus infection, it is often debilitating for patients. Common symptoms include nasal inflammation, postnasal drip, and a build-up of mucus in your nose and sinuses, leading to facial pressure and pain.

Some patients experience swelling around their eyes or tenderness around their nose, cheeks, or forehead. If your symptoms have continued for many weeks, you likely have chronic sinusitis.

What Causes Sinus Infection?

While most sinus infections begin with a virus, there are plenty of other sources. It's worth exploring potential causes of sinusitis in case there is an underlying reason you are dealing with this condition. Let's take a closer look at the most common causes of sinus infections.


If you are sensitive to allergens such as pollen, dust mites, mold, or pet dander, you may experience chronic sinusitis as your body launches an allergic reaction. Environmental and seasonal allergies are commonly behind chronic symptoms such as sinus pain, runny nose, and facial tenderness.

Physical Blockages

While not as common, physical traits can be behind your chronic sinusitis. Nasal polyps are benign, painless growths that can line your nasal passages. They result from chronic inflammation and can cause nasal congestion and discomfort. Similarly, a deviated septum—a misshapen or displaced nasal septum—can cause ongoing congestion and other symptoms.


If a sinus infection is not caused by allergies or physical obstruction, chances are good that it results from a viral infection. Many viruses, including those that cause a common cold, can quickly settle in the tissue lining of a sinus cavity and kick off the symptoms of sinusitis.


When sinusitis starts for any reason, fluid in the sinuses and nasal passages can become infected with bacteria. The build-up of mucus provides the perfect environment for bacterial sinus infections to start. This type of illness is serious and needs to be treated with medication before bacteria can spread elsewhere in your body.

Risk Factors

There are several risk factors for sinusitis, some of which are likely familiar. Knowing these factors can help you feel more in control as you take steps to prevent sinusitis where you can.

Existing Cold

First, an existing cold is the underlying cause of many sinus infections. A stuffy nose, post-nasal drip, and inflamed nasal tissue create pressure within your sinus and nasal cavities, creating discomfort and a general feeling of unwell.

Environmental or Seasonal Allergies

An important, often overlooked, risk factor for sinusitis is the presence of seasonal or environmental allergies. Whether you are allergic to dust, ragweed, or pollen or have other trigger allergies, they can cause chronic congestion and sinus pressure, leaving you with ongoing symptoms and a higher risk for a bacterial infection.


The risk factors over which you have more control include your exposure to cigarette and secondhand smoke. Effectively, smoke lowers your natural protection against sinus infections, as the toxins in smoke damage the cilia that protect the lining of your nose and sinuses.

Weakened Immune System

Naturally, you are at higher risk of any infection, including sinusitis, if your immune system is weakened for any reason. Maybe your system has always been weak, or perhaps you are on medication that dampens your immunity. In either case, you will be at greater risk for sinusitis if your immune system is compromised.

Structural Nasal Issues

Finally, if you have structural issues that impact the lining of your nasal passages—including polyps or damage to your nasal septum—you are also at higher risk.

While many of these factors are hard to control, it's important to take any steps you can to prevent sinusitis or minimize its risk. While some measures you can manage yourself, you will need medical attention for others.

When to See a Doctor

There are several reasons you should see a doctor concerning your sinus infection.

First, if your symptoms are suddenly worse or include new signs that your infection has turned bacterial, you should make an appointment. If you have a new headache, for example, or a sudden fever with facial pain, you should get checked out.

If your infection lasts more than ten days without improvement, you should also see a doctor. Chances are, an infection that lasts this long is bacterial and not viral.

If your symptoms are chronic—lasting a few weeks or more—and you're not sure what is causing them, you should see a doctor to ask if allergies might be underlying your congestion. They can run simple tests to get to the bottom of your infection.

Finally, if you are confident your sinus infection is not bacterial but still find yourself suffering from congestion and discomfort, speak to your doctor about over-the-counter medications you might use for additional symptom relief. These products can provide short-term relief, whether your infection is viral or related to allergies.

When in doubt about a sinus infection, see your doctor. If your congestion is chronic, you may want to know more about what causes your sinus infection, so you can better understand if allergies are behind your symptoms.

How is Sinusitis Diagnosed?

If you've had ongoing sinus pain and infection, you may be curious how your doctor would diagnose any underlying issues. Your doctor has several tools they can use to conclusively diagnose chronic sinusitis, including imaging, testing, and lab samples.

  • Allergy tests: If you have chronic symptoms and your doctor suspects allergies could be the root cause, they may recommend taking an allergy test. Wyndly’s at-home allergy test is an easy and convenient way to test your allergies from the comfort of your home.
  • Visual observation: Using a fiber-optic light on a thin tube, your doctor can look into your sinuses to see if there is any evidence of polyps, damage to your septum, or other structural issues.
  • Medical imaging: Through CT or MRI images, your doctor can assess the thickness of your sinus tissue and identify physical issues or troublesome inflammation of your nasal passages and sinuses.
  • Lab samples: Using swabs from the inside of your nose, your doctor may be able to determine if bacteria or fungi are at the root of your sinus infection. This information will help them decide whether or not antibiotics would be a helpful treatment.

Although a sinus infection can be frustrating, especially if it is chronic, it is essential to know that your doctor has tools available to help properly diagnose the source of your discomfort.


Standard treatment options for sinus infections will vary, depending on the nature of your infection. Effective treatment requires that you first understand the root cause of your symptoms.

Here are the most likely treatments your doctor will recommend, from cold medicines and antihistamines to—in rare cases—surgery.


If your infection has turned bacterial, your doctor will likely prescribe antibiotics to prevent its spread. A bacteria-based infection is more likely if your sinus infection lasts more than a week and causes symptoms like fever, jaw pain, tooth pain, bad breath, or blood in your nasal discharge.

Nasal Decongestant Sprays

These sprays can be purchased over the counter and used to help provide short-term relief for nasal congestion. While they don't get to the root of an infection, they can help thin the mucus and reduce swelling in the nose and nasal passages, providing temporary relief from the discomfort of congestion.


Antihistamines help to relieve the common cold symptoms that can accompany allergic reactions. If you suspect your sinusitis is linked to allergies, you might consider using antihistamines, which temporarily help to calm your immune system when it over-reacts to trigger allergens. Keep in mind there are different subtypes of antihistamines, each with its own side effects.

Nasal Corticosteroids

These medications are inhaled deep into the nose to help relieve a stuffy nose and other symptoms of nasal allergies. Only available with a prescription, this medication is sometimes used to help prevent the regrowth of nasal polyps when they have been removed by surgery. Side effects can include a stinging feeling, irritated throat, itchiness or swelling in the nose, or even nosebleeds.

Generally, nasal corticosteroids should not be used for more than a month at a time.

Nasal Saline Washes

A nasal wash is designed to thin mucus while flushing allergens, debris, bacteria, and mucus from your nasal passages. While you can use saline washes daily for short-term relief of sinusitis symptoms, it's important to note that they don't prevent sinus infections from starting.


In more severe cases, often when structural issues or recurrent sinusitis cause ongoing discomfort, a doctor may consider surgery to treat recurring sinus infections. Before you commit to surgery to treat chronic infections, be sure to ask if allergies could be the underlying cause.

Allergy Immunotherapy

Allergy immunotherapy is the best allergy treatment to desensitize your immune system to known allergens. With gradual exposure to trigger allergens, your body begins to recognize and accept their presence without launching an allergic reaction.

There are two forms of immunotherapy for allergies—allergy shots, which need to be administered by a doctor, and sublingual immunotherapy, which can be safely taken at home, using under-the-tongue drops or tablets. Learn more about sublingual immunotherapy.

Take Our Allergy Assessment

If you suffer from recurrent sinusitis and suspect that allergies might be to blame, find out how immunotherapy can provide lasting relief from allergy symptoms.

At Wyndly, our allergy doctors will take the time to understand your medical history, then create a personalized treatment plan, using sublingual immunotherapy to offer at-home, long-term allergy relief. To get started, take our brief online allergy assessment.

Common Questions and Answers

Naturally, if you suspect you have a sinus infection or chronic sinusitis due to allergies, you have plenty of questions. You may be worried that you could put others at risk or simply wonder what causes a sinus infection.

We're here to help with answers to common questions.

How long do sinus infections last?

While every infection is different, viral sinusitis usually lasts a week to ten days. If the infection becomes bacterial, it will last longer and produce more acute issues such as fever and facial pain. Recurrent acute sinusitis, a chronic condition, can last for twelve weeks or more.

How do sinus infections spread?

A sinus infection can only spread if an underlying virus is transmitted from one person to another. To be safe, use basic hygiene—wash your hands, cover your cough—to avoid viral spread through direct contact. Infections caused by bacteria or underlying allergies are not contagious.

Are sinus infections contagious?

Only sinusitis caused by a virus can spread from one person to another. Infections caused by structural issues, such as polyps or abnormalities in your nasal septum, or those caused by a chronic reaction to allergies or the growth of bacteria are not contagious.

Can You Get A Sinus Infection From Allergies?

The short answer is: yes. While your allergy symptoms—stuffy nose, fluid buildup in your sinus cavities, inflammation in the lining of your nasal passages—do not qualify as a sinus infection, they create the perfect environment for sinusitis to develop as bacteria multiply and magnify symptoms.

What Does A Sinus Infection From Allergies Feel Like?

Given the similarities between how you feel with a sinus infection caused by a virus or one caused by allergies, it can be hard to tell the difference. Allergic reactions tend to last longer, creating chronic symptoms of sinusitis that can lead to a more acute scenario.

What Happens if Sinusitis Isn't Treated?

Left untreated, sinusitis can lead to ongoing discomfort and a higher risk of bacterial spread as the air-filled cavities in your face fill with fluid. Your doctor may be wary of antibiotic resistance and may only prescribe medication if they are certain bacteria are present.

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