A Guide to Sinus Infection Symptoms
Sinusitis (sinus infection) is a common condition, especially if you live in allergen-laden areas of the country or are exposed to sick people all day. According to the Centers for Disease Control and Prevention, nearly 30 million US adults are diagnosed with chronic sinusitis yearly. This is roughly one in every eight adults.
The sinuses are air-filled cavities in the facial bones. Sinuses lighten the weight of facial bones and provide resonance for speech. Sinuses are lined by mucous membranes that have hair-like extensions called cilia. These membranes produce a watery fluid called mucus. Mucus contains antibodies and other chemicals that help keep the sinuses pathogen free.
Cilia move the mucus toward the sinus openings, where it drains into the nose. When these openings to the sinuses, called ostia, become clogged, mucus accumulates in the sinuses, setting the stage for a sinus infection.1
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Chronic vs. Acute Sinusitis
Sinusitis and rhinosinusitis refer to inflammation of the nasal cavity and sinuses. The inner lining of your nose and sinuses becomes swollen and irritated due to an infection. An acute infection is one that lasts less than four weeks. Anything lasting longer than four weeks is classified as subacute if it lasts between four and 12 weeks and chronic if it lasts longer than 12 weeks.
Causes of Sinusitis
When you blow your nose, pressure increases in the nasal and sinus cavities. This can cause reflux of contaminated mucus into the sinuses. When viruses (bacteria or fungi) enter the sinus cavity, this stimulates an immune response. Blood flow increases to the sinuses, and blood vessels become leakier. Fluid and immune cells leak into the surrounding tissues, increasing swelling and inflammation.
The most common cause of sinusitis is viral infections—the same ones that cause common cold symptoms.
Viral infections, such as rhinoviruses, influenza, and parainfluenza viruses, cause most acute sinusitis. Adults average two to three colds yearly, putting them at risk for sinusitis. Cold viruses can travel from the eyes or nose into the sinuses. They can also spread systemically through the bloodstream.2
Bacteria can also cause acute sinusitis. Typically, viral sinusitis lasts about 7 to 10 days, and bacterial sinusitis persists much longer.1
Chronic sinusitis is more of a chronic inflammatory process. What actually causes chronic sinusitis is unknown. A subset of chronic sinus infections may be infectious in nature. Commonly, treating chronic sinusitis with antibiotics leads to temporary improvement.
There are some parallels between allergies and chronic sinusitis. Severe allergies can cause symptoms that are very similar to chronic sinusitis. Allergies and asthma are inflammatory processes, as is chronic sinusitis.
Symptoms of sinusitis include:
- Facial pain or pressure
- Nasal congestion
- Nasal drainage
- Post-nasal drip
- Sore throat
- Tooth discomfort
- Ear pressure
- Bad breath
- Altered sense of smell
Symptoms of acute bacterial sinusitis include:3
- Discolored, thick nasal discharge
- Facial pain localized to the sinuses
Symptoms of chronic sinusitis include:
- Prolonged nasal congestion
- Reduced sense of smell and taste
- Bad breath (halitosis)
Conditions That May Be Confused for Sinusitis
Several conditions may be confused with sinusitis, including:
- Allergies: Common seasonal allergies cause symptoms that overlap with sinus infections. It can be difficult to distinguish between the two conditions. Allergies symptoms can be seasonal, so the timing of your symptoms may help you determine whether you have sinusitis or allergies.
- Migraine: Sinusitis and migraine can cause similar types of headaches. Both conditions can cause headaches behind the eyes, cheeks, and under the bridge of your nose.
- Vasomotor rhinitis: Changes in temperature, humidity, or exposure to strong odors can cause congestion, sneezing, and runny nose. This condition, called vasomotor rhinitis, causes symptoms similar to sinusitis.
- Nasal polyps: These noncancerous growths in the nose or sinusitis can cause similar symptoms to sinusitis. Nasal polyps can occur with chronic sinusitis.
- COVID-19: COVID is a viral infection that causes upper respiratory symptoms and can lead to sinusitis. It can be difficult to tell the difference between sinus infections and COVID.
What Does a Sinus Infection Feel Like?
Many people describe sinus infections as pressure or pain in the cheeks, under the bridge of the nose, or behind the eyes that worsen when leaning forward. Inflammation of the sinuses can cause pain in the upper jaw teeth, which causes many people with sinus infections to see a dentist first with a concern that they have a cavity.
Signs You Should Go to a Doctor
It can be really difficult to tell whether you have a viral infection or sinusitis. One clue is when an upper respiratory infection or cold persists for a week to 10 days or the symptoms seem to improve and then worsen. Call your doctor if you have a persistent infection or any concerns about immune function.
Many providers see patients for sinusitis, so finding a doctor on call to evaluate your symptoms and provide an online diagnosis is relatively easy, and many provide 24-hour access—doctor access whenever you need it. If your online doctor believes that you have bacterial sinusitis and need an antibiotic or severe allergies that need treatment, they can send an online prescription to an online or local pharmacy.
While rare, sinusitis is associated with some serious potential complications, including:
- Cellulitis: Infection of the eye or the tissues around the eye is a potentially serious complication that, when untreated, can cause blindness or infections in the tissues around the brain.
- Meningitis: The sinuses are anatomically close to the meninges, which are coverings over the brain and spinal cord. Meningitis is when these membranes become inflamed or infected.
- Osteomyelitis: If an infection spreads outside the sinuses and into the bones, a serious condition called osteomyelitis may occur.
Maintaining mucus flow through the sinuses can help prevent sinusitis. Steps you can take to protect your sinuses from inflammation and infection include:
- Avoid pollutants and allergens
- Stop smoking
- Avoid touching your face and eyes
- Rinse your sinuses with a saline solution
- Use a humidifier to thin secretions
- Stay hydrated
- Treat medical conditions such as gastroesophageal reflux disease or enlarged tonsils and adenoids
While we strive to always provide accurate, current, and safe advice in all of our articles and guides, it’s important to stress that they are no substitute for medical advice from a doctor or healthcare provider. You should always consult a practicing professional who can diagnose your specific case. The content we’ve included in this guide is merely meant to be informational and does not constitute medical advice.
- Leung RS, Katial R. The diagnosis and management of acute and chronic sinusitis. Prim Care. 2008 Mar;35(1):11-24, v-vi. doi: 10.1016/j.pop.2007.09.002. PMID: 18206715.
- Friedman RA, Harris JP. Sinusitis. Annu Rev Med. 1991;42:471-89. doi: 10.1146/annurev.me.42.020191.002351. PMID: 2035989.
- Morcom S, Phillips N, Pastuszek A, Timperley D. Sinusitis. Aust Fam Physician. 2016 Jun;45(6):374-7. PMID: 27622225.