What Is Sinusitis?

Your sinuses are clogged and your face hurts from the pressure. You might say you have "a sinus infection" or "sinusitis." Your doctor, though, might call it something else.

"When clinicians talk amongst ourselves, we talk about rhinosinusitis," says Martin J. Citardi, MD, chair of the Department of Otorhinolaryngology-Head & Neck Surgery at McGovern Medical School at the University of Texas Health Science Center at Houston. "It's inflammation of the sinus lining and nasal lining together that causes patients' symptoms," he tells Health.

No matter what you call it, sinusitis can make you feel pretty uncomfortable, like having a really bad cold, says the American Academy of Otolaryngology-Head and Neck Surgery Foundation (AAO-HNS). While some people get better in a matter of days, others have symptoms that linger for weeks.

What Is Sinusitis, Exactly?

Sinusitis (or rhinosinusitis) is inflammation of the tissue lining the sinuses and nose, per the World Allergy Organization.

To understand what happens when sinusitis strikes, consider the anatomy of your upper airway. Behind your forehead, in your cheeks, and alongside your nose lie four hollow spaces. These air-filled pockets are your sinuses, explains the National Institutes of Health. Sinuses affect the pitch and quality of your voice, and they reduce the weight of your head. But your sinuses' real claim to fame is producing mucus.

Mucus serves an important purpose: It helps trap dust, dirt, pollutants, and germs that enter your nose, says the American College of Allergy, Asthma, & Immunology. Tiny hair-like structures called cilia naturally sweep the mucus into the back of your throat where it can be swallowed.

At least that's what's supposed to happen. But if that defense mechanism fails, a germ, allergen, or other irritant can trigger swelling that blocks normal sinus drainage, per the Cleveland Clinic. Suddenly, you've got a lot of mucus in your sinuses with nowhere to go, leading to sinus pain and pressure, says the American Academy of Family Physicians (AAFP).

"A very common source of that inflammation is an infection," Timothy R. Boyle, MD, an otolaryngologist with the Marshfield Clinic Health System in Wisconsin, tells Health. Often the culprit is a rhinovirus—the type of virus responsible for the common cold.

The type of inflammation that occurs in the sinus lining is very similar to what happens in the lungs, Dr. Citardi points out. "So patients with asthma have inflammation of their lung tissue—their bronchioles and lung passages," he says. "The mechanisms that drive that inflammation seem also to be active in the nose."

Types of Sinusitis

Here's how the AAO-HNS Foundation breaks down the different types of sinusitis:

Acute: Symptoms lasting up to four weeks. (Many cases will resolve on their own within 10 days, the Cleveland Clinic notes.) Acute sinusitis can be further classified by the cause of the inflammation. These are the two main causes:

• Viral. Most cases of acute sinusitis are caused by viruses.

• Bacterial. Persistent or worsening symptoms may be a sign of acute bacterial rhinosinusitis.

Subacute: Symptoms lasting four to 12 weeks.

Chronic: Symptoms that persist for 12 weeks or longer.

Recurrent: Having four or more sinusitis episodes a year with no symptoms in between.

Symptoms of Sinusitis

Sinusitis can cause a range of symptoms. Per the US Centers for Disease Control and Prevention (CDC), common symptoms include:

• Runny nose
• Stuffy nose
• Facial pain or pressure
• Headache
• Post-nasal drip
• Sore throat
• Cough
• Bad breath

In addition to these common signs, people with chronic sinusitis may have other symptoms. According to the Cleveland Clinic, they include:

• Thick yellow or green nasal discharge
• Toothache
• Ear pain
• Cough
• Tiredness
• Loss of taste and smell

If your symptoms are due to a bacterial infection, you're more likely to have a fever as well, notes Cedars-Sinai.

Sinusitis Causes

A number of things can cause the lining of the nose and sinuses to swell up or boost your risk of developing sinusitis:

Infections

Viruses. The same germs that cause a cold or other respiratory tract infections are often responsible for acute sinusitis, per a review published by the US National Library of Medicine (NLM).

Bacteria. Different types of bacteria, like the strain that causes pneumonia, can infect the lining of your nose, then spread into your sinuses, says Cedars Sinai.

Fungi. Although much less common, fungal infections can cause sinusitis, especially in people with weakened immune systems, per the NLM.

Airway Inflammation

Allergens. Sometimes allergies to dust, dander, smoke, or mold, for example, can trigger inflammation of the nose and sinus tissue, says NLM. Seasonal allergies (hay fever) can also lead to inflammation that blocks your sinuses, per Mayo Clinic.

Chronic conditions. Blocked airways due to asthma or conditions such as cystic fibrosis can be a factor in the development of chronic sinusitis, says the Cleveland Clinic.

Physical Obstructions

A deviated septum. You may be at greater risk of developing chronic sinusitis if your septum, the wall of cartilage dividing your nose into two chambers, is off-center, notes the Mayo Clinic.

Nasal polyps. These benign growths on the lining of the nasal or sinus tissue can obstruct your airway, leading to chronic sinusitis, says Mayo Clinic.

How Is Sinusitis Diagnosed?

A diagnosis of acute sinusitis is based on symptoms and medical history, says the Cleveland Clinic. Your health care provider will examine your ears, nose, and throat, looking specifically for signs of inflammation, blockage, or infection.

Sometimes additional testing may be performed to help rule out other causes, according to the Mayo Clinic. (More on that below.)

When symptoms last 12 weeks or longer, chronic sinusitis may be suspected. Your health care provider will examine you and ask you about your medical history.

Testing may include:

• Nasal endoscopy. A very thin tube with a light can be inserted into your nose to get an up-close look at your sinuses.
• Imaging. A CT scan, for example, may reveal structural issues or deep inflammation.
• Tissue samples. While not routine, sometimes a small culture from your nose or sinuses can be helpful in identifying bacteria or fungi.
• Allergy testing. This can be helpful if your symptoms are caused by an allergen.

How Is Sinusitis Treated?

Most cases of acute sinusitis resolve on their own within 10 days. You may not need any treatment at all, or maybe a little something to soothe your symptoms. To feel better, the Cleveland Clinic says your health care provider may suggest:

• An OTC decongestant
• An OTC pain reliever
• Warm compresses placed over your nose and forehead to ease painful sinus pressure
• Saline nasal spray to flush out excess mucus
• Medicated nasal spray, but limit use to no more than three days unless otherwise directed
• Fluids to help thin your mucus
• Rest

Treatment for chronic sinusitis may depend on the cause. The Mayo Clinic says possible options include:

• Corticosteroid nasal spray
• Oral steroids
• Other medications to treat underlying conditions (such as antihistamines for allergy or anti-fungal treatments)
• Surgery (to clear obstructions)

If your sinus infection is caused by a virus, antibiotics won't do any good, the Cleveland Clinic points out. (And taking them when they're not necessary could lead to an antibiotic-resistant infection.) But if your symptoms last more than 10 days or suddenly worsen after you thought you were getting better, you might need an antibiotic.

How Do You Prevent Sinusitis?

The best way to ward off sinusitis is to avoid exposure to viral infections (like the common cold and seasonal flu) and other potential triggers. The CDC, Cleveland Clinic, and other experts offer these tips:

• Wash your hands often
• Treat your asthma, allergies, and other underlying conditions
• Don't smoke and avoid secondhand smoke
• Use a saline rinse
• Moisten the air breathe using a humidifier, if needed
• Avoid being around other people with upper respiratory infections
• Stay hydrated, exercise, and eat a healthy diet
• Get a flu shot

When to See Your Health Care Provider

Although you might feel like you're coming down with a case of sinusitis, in most cases you won't need to see a doctor, per the Mayo Clinic. (That's because viral infections usually clear up on their own.)

So what can you do? You might want to consider using a decongestant nose spray or taking an oral decongestant, says Dr. Boyle. Some Tylenol or ibuprofen can help with aches and pains, he says. Then see how it goes.

But if you're not feeling better in seven to 10 days—say your nasal secretions get heavier and thicker—"that's an indication that things aren't going away," says Dr. Boyle. You may need to seek care and, yes, you might benefit from an antibiotic.

Mayo Clinic suggests seeing your provider if:

• Your symptoms fail to improve or get worse
• You're running a fever higher
• You have a history of chronic or recurrent sinusitis

Some symptoms may indicate a serious infection. Seek immediate medical attention any time you experience:

• Eye pain or swelling or changes in vision
• High fever
• Neck stiffness
• Confusion