What is Sinusitis?

Table Contents

Sinusitis is a sinus infection. It can occur when mucus builds up in the air-filled pockets in the sinuses, causing a stuffy nose. When mucus builds up, the sinuses react when exposed to allergens, irritants or respiratory viruses. This causes the tissue lining in the sinuses to become inflamed and swollen, leading to more mucus.

As mucus accumulates in your sinuses, it creates a breeding ground for germs. Infection can set in, causing sinus pressure, inflammation and pain.

Rhinosinusitis is similar in that it occurs when there’s inflammation in the nose as well as the sinuses.

Woman sitting on her couch holding her nose with both hands and a tissue. She is suffering from sinusitis.

Who has sinusitis?

Sinusitis statistics from the U.S. Centers for Disease Control and Prevention (CDC) show 28.9 million adults in the United States develop the condition each year. It often develops as a complication after a cold virus or the flu. People who have asthma, allergies or weakened immune systems are at high risk for sinus infections.

What are sinuses?

Sinuses are air-filled spaces in the nose. They are lined with tissue and mucus. There are four pairs of sinuses in the face: the ethmoid, maxillary, frontal, and sphenoid.

  • Ethmoid sinuses – located towards the top of your nose, surrounding the bridge (or where a pair of glasses would rest).
  • Maxillary sinuses – located next to your lower nose and over the cheekbones. This is the largest of the four sinuses.
  • Frontal sinuses – located on the forehead, just around and above the eyebrows.
  • Sphenoid sinuses – located behind the nose, more inside the face than the other three sinuses.

The ethmoid and maxillary sinuses are present at birth. The frontal sinuses develop in mid-childhood. The sphenoid sinuses develop in adolescence.

Infographic of healthy sinuses vs. sinusitis. Half the person is showing a cut-out of clear nasal passages. The other half is showing where mucous fills up in the naval cavities.

What are the signs and symptoms of sinusitis?

Common signs and symptoms include:

  • Sinus headache
  • Postnasal drip (fluid from your nose draining into the back of the throat)
  • Nasal congestion
  • Runny nose with green or gray discharge
  • A feeling of pressure or pain on the face
  • Cough
  • Fatigue
  • Loss of sense of smell
  • Upper tooth pain
  • Sometimes low-grade fever
  • Bad breath

Sinusitis may occur after an upper respiratory tract infection such as the flu or common cold. It may occur due to allergy-related conditions such as allergic rhinitis.

What are the causes of sinusitis?

Sinusitis is most often caused by a viral, fungal or bacterial infection. But certain conditions place you at increased risk, such as:

  • Infections. Any infection that causes inflammation in the sinuses and increased mucus production can put you at risk.
  • Seasonal allergies (also called “hay fever”). These often cause nasal inflammation and increased mucus production. This provides a breeding ground for germs.
  • Structural abnormalities. Anything that changes the structure of the nose and sinuses may disturb the flow of secretions. This may cause a buildup of mucus. Some structural abnormalities include nasal polyps, a deviated nasal septum, cleft palate or tumors.
  • Environmental factors. Exposure to irritants can cause inflammation and increase mucus production. These may include tobacco smoke, exposure to secondhand smoke, vaping aerosol, chemicals, fumes or allergens.
  • Medications. Certain medications may increase congestion. These may include birth control pills, medications for high blood pressure or depression. Medication that suppress the immune system also increases risk of sinus problems. Do not stop taking medicines without consulting with your doctor first. Ask if any medicine you’re taking may contribute to your sinus problems.
  • Medical conditions. Certain medical conditions, including respiratory diseases such as asthma, gastroesophageal reflux disease (GERD), cystic fibrosis and immune and autoimmune disorders, may put people more at risk.
  • Other causes. Foreign objects in the nose, facial trauma or dental infections can lead to sinus problems.

Young girls holding tissue to her  nose because of stuffed nasal passages.

What causes sinus pain?

Sinuses can become congested just like your nose. This may be a reaction to allergens, irritants or respiratory infections. Tissues become swollen and produce extra mucus.

If the cilia (tiny hairs in your respiratory tract) can’t move the thick mucus out, the mucus begins to accumulate. Trapped mucus provides a safe haven for germs or fungi to grow. Infection sets in, causing sinus pressure and pain.

Differences in air pressure can also cause sinus pain. When your sinuses are clogged, air can’t pass in and out easily. Any atmospheric changes in pressure can create a painful build-up. This could occur from driving through the mountains, flying in a plane, or diving in the ocean.

Are there different types of sinusitis?

The most common type is the quickly resolving acute form. But there are actually several different types. These include:

  • Acute – resolves within 4 weeks or less. Many acute cases are viral and do not require antibiotics. They often resolve with over-the-counter medications and treatments.
  • Chronic – lasts for 8 weeks or more. This could be due to recurrent infections or inadequate treatment.
  • Subacute – lasts between 4-8 weeks; in between acute and chronic.
  • Recurrent – recurs 3 or more times in a year; usually acute.
  • Fungal – there are multiple types of non-invasive and invasive fungal sinusitis. These are caused by a fungal infection and classified based upon how invasive they are in the sinuses. Non-invasive types are only in the nose and sinus areas. Invasive types can spread outside the nasal and sinus cavities to the eyes and brain. These are more common in people with compromised immune systems. Treatment for both is normally surgery.
    • Non-invasive fungal: fungal ball (FB), saprophytic fungal sinusitis (SFS), and allergic fungal rhinosinusitis (AFRS).
    • Invasive fungal: acute invasive rhinosinusitis (AIRS), chronic invasive rhinosinusitis (CIRS), and granulomatous invasive sinusitis (GIFS)
  • Chronic Rhinosinusitis with Nasal Polyps (CRSwNP)people with CRSwNP have chronic rhinosinusitis lasting more than 12 weeks and nasal polyps (non-cancerous, painless growths lining the nasal passage). This is more common in males and people with allergic rhinitis and asthma.

Doctor examining hispanic woman for sinus inflammation.

How is sinusitis diagnosed?

Most cases can be diagnosed by your healthcare provider. The diagnosis includes a review of your medical history and a physical exam. If you are experiencing recurrent and/or chronic sinusitis, your healthcare provider may recommend additional diagnostic testing. This may include:

  • Allergy testing – if allergies are suspected, you may need testing. Your healthcare provider may send you to an allergy specialist for skin prick testing to look for potential allergens. Identifying an allergen can help with prevention and treatment options. Treatment may include medications and allergen immunotherapy (also called allergy shots).
  • Rhinoscopy or nasal endoscopy – a tube with a light is inserted up your nose to look for structural abnormalities (such as nasal polyps).
  • Imaging – if nothing is seen looking into the nose, then your healthcare provider may order further testing. A CT scan or MRI allows them to visualize other areas of the sinuses.

Treatment options may vary based upon whether your condition is acute, chronic or recurrent.

Acute sinusitis treatment

Many cases clear up by themselves within a week. However, it’s best to seek medical care if symptoms continue for 7 days or longer.

The goal of treatment is to reduce the inflammation. Antibiotics are standard treatments for bacterial sinus infections that persist beyond 7-10 days. These are designed to attack the bacteria. But remember, many acute cases are caused by viruses, which will not respond to antibiotics.

  • Nasal corticosteroid sprays can reduce inflammation and swelling caused by allergies or nasal polyps. These nasal sprays start working quickly but take 4-5 days to reach full effect.
  • Nasal decongestant sprays, pills and liquids can help shrink inflamed and swollen nasal areas. They also allow mucus to flow out more easily. Nasal decongestant sprays should not be used for more than 3-5 days because long-term use can actually increase congestion.
  • Antihistamines fight the inflammation caused by an allergic reaction.

If your symptoms last 8 weeks or longer or recur 4-6 times during the year, this indicates a chronic or recurrent case. These severe cases require a more comprehensive treatment. Talk with your doctor about prescription medicines.

Recurrent and chronic sinusitis treatment

For recurrent or chronic cases, treatment must focus on the “why.” Ask your doctor why you continue to experience sinus problems and if you are developing chronic sinusitis. Your healthcare provider may order diagnostic testing to look for underlying conditions.

Some other questions to ask:

  • Do you have poorly controlled allergies? If so, then allergy management could be part of the treatment plan. Intranasal steroids may be used to treat and reduce inflammation.
  • Do you have severe asthma and require frequent corticosteroids? Chronic sinusitis and asthma often go hand in hand, so make sure to get your asthma treated.
  • Do you have a compromised immune system from medications or diseases (such as cancer or HIV)? Then make sure those conditions are appropriately managed by you and your healthcare team.
  • Do you have a fungal infection or structural issue? In some cases, surgery to correct structural issues or remove fungi is needed.

All treatment options should be discussed with your healthcare provider.

Are there home remedies for sinusitis relief?

Many cases can be managed at home. Moist compresses to the sinuses, lots of fluids, steam (from showers or just hanging your head over a hot bowl) and nasal rinses may all help. These remedies help open the clogged passages and soften mucus.

Avoid smoking or inhaling cigarette smoke as this can worsen your sinuses and breathing.

Preventing sinusitis

Make sure you have healthy sinuses. This will help prevent sinusitis. You can prevent most sinus problems by reducing risk factors:

  • avoiding illnesses and seasonal allergies that cause sinus inflammation;
  • staying hydrated so that you can keep nasal mucus thin and cilia moving; and
  • washing your nasal area regularly.

Minimize respiratory infections

  • Wash hands often and keep them out of your mouth and eyes.
  • Get your recommended vaccines, including flu, COVID-19 and pneumococcal vaccines. All are recommended for people more prone to respiratory infections.

Control allergies

  • Consult with your doctor to identify what you are allergic to, and then take steps to reduce your exposure.
  • Use allergy medications as prescribed by your doctor.
  • Consider treating hard-to-control allergies with immunotherapy to build tolerance to your allergens.

Apply moisture and heat to your face

  • Place a warm, moist washcloth over your face several times a day to soften mucus.
  • Drink lots of fluids to keep your sinuses hydrated; avoid alcohol and caffeine, which can have a drying effect.
  • Inhale steam (from a hot shower or bath) to moisten and soften mucus.
  • Keep nasal passages moist with saline sprays that can also rinse out mucus.
ConditionSymptomsOnset of SymptomsTypical Duration
ALLERGIESCongestion, runny nose with thin and watery discharge, sneezing, weakness and fatigueSymptoms begin almost immediately after exposure to allergen(s). Seasonal allergy symptoms occur at the same time every year. Perennial allergy symptoms are present year-round. Symptoms last as long as you are exposed to the allergen(s). If the allergen is present year-round, symptoms may be chronic.
COLDRunny nose with watery-to-thick yellow discharge, low-grade fever, sneezing, weakness and fatigue Symptoms develop within 1-3 days of exposure to a cold virus. Typically 7-10 days.
FLUFever with chills, headache and body aches, cough, sore throat, nasal congestion and runny nose, extreme exhaustion and weakness, sometimes vomiting Symptoms develop within 1-3 days of exposure to flu virus. Typically 5-10 days.
SINUSITISCongestion, green or gray nasal discharge, postnasal drip, a feeling of pressure on the face, cough, headache, loss of sense of smell, tooth pain, sometimes feverSymptoms develop as a complication after a cold. Can also be triggered by allergies. Can last weeks, months and even years if ignored.

What is the relationship between sinusitis and asthma?

Many studies show a connection. Sinusitis has been associated with more severe cases of asthma. Studies show about half of people with moderate to severe asthma also experience chronic sinus infections.

Sinusitis can make managing asthma harder. It can sometimes stoke airway inflammation, causing breathing problems related to asthma. It can also worsen asthma symptoms, including coughing, wheezing, shortness of breath and chest tightness. And it can disturb nighttime sleep, a common problem for many people with asthma.

When you treat sinus problems with medication, you can sometimes relieve asthma symptoms. You should continue to take your daily asthma controller medication and use a quick-relief inhaler at the first sign of asthma symptoms. Keeping your asthma under control can reduce your risks of developing a severe sinus infection.

If you have allergic asthma, it’s important to identify and avoid allergens that may trigger your asthma symptoms. These may include grass, tree and weed pollen, indoor and outdoor mold, and indoor allergens such as pet dander and dust mites.

Can sinusitis cause…

  • Ear pain? Yes, from inflammation and pressure.
  • Sore throat? Yes, from postnasal drip.
  • Fever? Yes, from a viral infection.
  • Headaches? Yes, from inflammation and pressure.
  • Nausea? Yes, but it’s not common.
  • Coughing? Yes, from postnasal drip.
  • Dizziness? Yes, from pressure it causes to the tubes of the ear.
  • Tinnitus? Yes, from pressure it causes to the tubes of the ear.
  • Asthma flare? Yes, from exposure to an allergen or postnasal drop.
  • Tooth pain? Yes, from inflammation and pressure. This is most specific to the upper back teeth, which are closest to the sinuses.
  • Sleep apnea? Yes, from decreased flow to the airways. Treating it is essential to treating the sleep apnea.
  • Vision problems? Yes, due to inflammation and pressure. In severe cases, it can lead to loss of vision due to pressure on the optic nerve.

Sinusitis Questions & Answers (Q&A)

Here are questions that are most often asked from people with sinusitis and/or their caregivers. If there’s something you’d like to see covered, please email Gary Fitzgerald, Editor.

How do I know if I have sinusitis?

Your healthcare provider will diagnose the condition and review your medical history. If you have congestion, sinus headaches, nasal discharge or any other sinus symptoms, this suggests sinusitis.

What is the root cause of sinusitis?

The root cause is inflammation and increased mucus production in the sinuses and nasal passages. Many things trigger inflammation and increased mucus production, including allergens and viruses.

What are the stages of sinusitis?

  1. Acute – this stage lasts 4 weeks or less. Symptoms may resolve with or without medical treatment. If they last more than 7-10 days, seek medical care.
  2. Subacute – this stage lasts between 4-8 weeks. Symptoms persist despite seeking medical care.
  3. Chronic – this stage lasts 8 or more weeks. Symptoms continue and you may need to consult a doctor to look for underlying medical conditions.

How long should sinusitis last?

Most cases last less than four weeks. If you are still experiencing symptoms after a week, you should seek medical care. Any symptoms beyond four weeks point towards a subacute or chronic symptoms.

Is sinusitis contagious?

In and of itself, sinusitis is not contagious. But if it results from an infectious diseases such as a cold or the flu, those viruses are contagious.

Who can treat sinusitis?

Family physicians or primary care providers can treat most cases. But recurrent or chronic sinusitis symptoms may require seeking care from a specialist. These include an ear, nose and throat (ENT) provider or an allergist (if allergies are suspected).

Why does my sinusitis keep coming back?

Recurrent sinusitis points towards an underlying condition, such as unmanaged allergies or structural issues in the nose. If your sinus problems come back or worsen, it is important to see a healthcare provider to look for underlying conditions.

Will a sinus infection go away on its own?

Many cases will go away on their own as they are often viral. Similar to a cold or the flu, they run their course. But if your symptoms last more than a week, then you should see your healthcare provider.

What is the fastest way to get rid of sinus infections?

Rest and staying hydrated are essential to getting better as quick as possible. You can also try warm compresses to your sinuses and things to help loosen and thin out the mucus (such as steam or nasal rinses). If your symptoms persist despite treatment at home, make an appointment with your healthcare provider.

How can I treat sinusitis at home?

Rest, fluids, warm compresses, hot showers or steam showers/baths, and nasal rinses are all recommended treatments.

What is the difference between sinusitis and a sinus infection?

They are the same thing. Sinusitis is the medical term while sinus infection is the laypersons term.

Are both sinusitis and rhinosinusitis the same?

No, but you will sometimes see them used interchangeably. Sinusitis is diagnosed based upon inflammation or swelling in the sinuses. Rhinosinusitis involves inflammation or swelling in the nose in addition to the sinuses.

Can I have sinusitis without mucus or congestion?

While mucus and congestion are hallmarks of the condition, not everyone has those symptoms. Some people may just feel sinus pressure or headaches.

What foods should I avoid with sinusitis?

Avoid alcohol and caffeine as these can dry out your nasal passages and sinuses. It is important to stay well hydrated. There is a belief that milk and dairy increase mucus production and so they should be avoided. But that is a myth.

Clinical evidence suggests that probiotics (which can be found in things like yogurt) may decrease the frequency and length of respiratory infections.

Is sinusitis an upper respiratory infection?

It is a type of upper respiratory infection. Colds, the flu, laryngitis and strep throat are some other types of upper respiratory infections.

Should I get an X-ray or CT scan of my sinuses when I have sinusitis?

Imaging tests such as x-rays or CT scans are not normally indicated. For recurrent or chronic symptoms, your healthcare provider may order imaging to check for structural abnormalities or other potential causes.

What complications are associated with sinus infections?

Most cases are easily treated, but there are potential complications. These may include:

  • eye infections;
  • skin problems such as cellulitis;
  • bone infections (osteomyelitis);
  • meningitis.

That is why it’s important to seek medical care if your symptoms persist for more than 7-10 days.

Will I need to make lifestyle changes to deal with a sinus infection?

Make sure to get adequate rest, practice good hand hygiene and get preventative vaccines. Make sure any chronic conditions are well controlled. Do not smoke tobacco and avoid secondhand smoke.


Reviewed by:

Ruthie Marker, MSRC, RRT, RRT-NPS, AE-C, LSSYB, a respiratory therapist with more than 13 years of experience working in adult critical care, neonatal care, and patient education. She joined Allergy & Asthma Network to support the Not One More Life program as a Spanish-speaking Asthma Coach. Ruthie has worked as a respiratory therapist in Texas all of her career and has supported COVID-19 efforts in Maryland and Arkansas.