About 31 million Americans are affected by a sinus infection each year. Microorganisms, like viruses, bacteria, or fungus, can take over one or more sinuses and trigger a sinus infection, also known as “sinusitis.”
Sinuses are four pairs of moist and hollow air-filled cavities located behind the forehead, nose, cheekbones, and in between the eyes. Each sinus has an opening that connects it to the inner nose. Sinuses produce specialized mucus that helps form a protective layer that moisturizes the nose and protects the airways from pollutants, dust, and microorganisms. Sinuses also help our voices resonate and sound healthy.
Symptoms of sinusitis include the following:
- Nasal congestion
- Facial pressure, pain or tenderness
- Puffiness around eyes
- Ear congestion or fullness
- Headache or toothache
- Thick purulent nasal or postnasal drainage
- Reduced sense of smell or taste
- Bad breath (halitosis)
- Sore throat
Sinus infections caused by viruses are the most common type of sinus infections, accounting for 90% to 98% of all cases.
Symptoms of viral sinusitis can almost always be treated at home and symptoms usually resolve within 7–10 days. Treatment for viral sinusitis often includes nasal saline rinses, intranasal steroids, decongestants, and over-the-counter medications for fever and pain. It is important to know that healthcare providers do not prescribe antibiotics for viral sinusitis. Your healthcare provider will recommend treatment options that are the most appropriate for you.
Bacterial sinusitis is much less common than viral sinusitis and accounts for 0.5% to 2% of all sinusitis cases. Bacterial sinus infections commonly occur when viral sinus infections do not resolve on their own.
At first glance, bacterial sinusitis can be hard to distinguish from viral sinusitis. The Infectious Diseases Society of America (IDSA) lists three specific criteria for the diagnosis of acute bacterial sinusitis:
- Symptoms last 10 days or longer and do not show clear signs of improvement;
- Symptoms initially improve but then get worse within a short time frame;
- Symptoms are severe, are accompanied by a fever of 102° Fahrenheit or higher, and last 3–4 days or longer.
Potential complications of untreated bacterial sinusitis include eye infection, sinus cavity blood clot, meningitis, brain abscess, and bone infection of the face or skull. If you suspect you have a bacterial sinus infection, it is important to see your healthcare provider right away. Symptoms may be treated the same way as viral sinusitis, but your healthcare will often prescribe an appropriate antibiotic to prevent complications from bacterial sinus infections.
Fungal sinus infections occur less frequently than either viral or bacterial sinusitis. Fungal sinusitis occurs when inhaled fungal spores colonize sinus tissues and cause an infection.
Symptoms of fungal sinusitis are usually identical to those of viral and bacterial sinus infections, but they are trickier to diagnose. People with healthy immune systems are rarely affected; they may develop “non-invasive” fungal sinusitis, which is typically a long-lasting sinus infection (more than three months).
Individuals with a weakened immune system due to conditions such as HIV, cancer, chemotherapy, or advanced diabetes are at higher risk for “invasive” fungal sinus infections, which can lead to changes in mental status, neurologic deficits, and decreased vision. An invasive fungal sinusitis that develops rapidly, within four weeks, is a true medical emergency; it could lead to death if not treated immediately.
Strategies for preventing sinus infections include nasal saline irrigation and nasal saline sprays, which help keep your nose moist and your sinuses clear of blockages that can lead to infection. Staying well-hydrated and avoiding dry environments by using a humidifier also help keep mucus in your nose thin and prevent backup into your sinuses. Keeping allergies under good control helps minimize sinus irritation and inflammation and reduces the risks of a sinus infection. Avoiding areas with high levels of pollution and avoiding exposure to smoke and other irritants as much as possible help keep sinuses clear.
Your chances of warding off many kinds of infections, including sinus infections, increases with good hand hygiene. Maintaining a healthy lifestyle based on a balanced diet, regular physical activity, mental fitness, and healthy sleep patterns helps to ensure proper functioning of various body organs and structures (including the sinuses) and maintain a strong immune system capable of defending the body against pathogens.
Amanda Chan, “Sinus Infections: 90 To 98% Are Caused By Viruses, Guidelines Say,” HuffPost, November 15, 2012, https://www.huffpost.com/entry/sinus-infection-guidelines-antibiotic-resistance_n_1368290
Anthony Chow, Michael Benninger, et al., “IDSA Clinical Practice Guideline for Acute Bacterial Rhinosinusitis in Children and Adults,” Oxford Academic, April 15, 2012, https://academic.oup.com/cid/article/54/8/e72/367144
Cedars Sinai, “Sinus Conditions & Treatments,” https://www.cedars-sinai.org/programs/sinus-center/conditions.html
Charles Patrick Davis, “Sinus Infection (Sinusitis),” MedicineNet, https://www.medicinenet.com/sinusitis/article.htm
Cleveland Clinic, “Chronic Sinusitis: Management and Treatment,” https://my.clevelandclinic.org/health/diseases/17700-chronic-sinusitis/management-and-treatment
Cleveland Clinic, “Fungal Rhinosinusitis,” https://my.clevelandclinic.org/health/diseases/17012-fungal-rhinosinusitis
Derek DeBoer, Edward Kwon, “Acute Sinusitis,” StatPearls, November 21, 2020, https://www.ncbi.nlm.nih.gov/books/NBK547701/
Gary Cox, John Perfect, Benjamin Bleier, “Fungal rhinosinusitis,” UptoDate, March 12, 2020
Harvard Health Publishing, “What to do about sinusitis,” January 29, 2020, https://www.health.harvard.edu/diseases-and-conditions/what_to_do_about_sinusitis
Hassan Ramadan, “Fungal Sinusitis,” Medscape, March 17, 2020, https://emedicine.medscape.com/article/863062-overview#a1
Kathleen Davis, “Everything you need to know about sinus infection,” Medical News Today, March 16, 2017, https://www.medicalnewstoday.com/articles/307190
Lana Bandoim, ” Sinus Infections: Are They Contagious?,” Healthline, June 2, 2017, https://www.healthline.com/health/are-sinus-infections-contagious#transmission
Live Science, “Most Sinus Infections Don’t Require Antibiotics, New Guidelines Say,” May 30, 2013, https://www.livescience.com/36211-sinus-infection-guidelines-isda.html
Mas Takashima, “Ten tips to avoid sinus infections,” Baylor College, June 25, 2014, https://blogs.bcm.edu/2014/06/25/ten-tips-to-avoid-sinus-infections/
MySinusitis, “Sinuses: What are they and what do they do?,” https://www.mysinusitis.com/blog/sinuses-what-are-they-and-what-do-they-do/
Peter George Deutsch, Joshua Whittaker, Shashi Prasad, “Invasive and Non-Invasive Fungal Rhinosinusitis—A Review and Update of the Evidence,” Medicina 55, no. 7 (2019): doi: 10.3390/medicina55070319
Richard Deshazo, “Syndromes of invasive fungal sinusitis,” Oxford Academic, January 1, 2009, https://academic.oup.com/mmy/article/47/Supplement_1/S309/1075356
Shawn Bishop, “No Matter the Cause, Symptom Relief from Chronic Sinusitis is Available,” Mayo Clinic, July 22, 2011, https://newsnetwork.mayoclinic.org/discussion/no-matter-the-cause-symptom-relief-from-chronic-sinusitis-is-available/
Zara Patel, Peter Hwang, “Patient education: Acute sinusitis (sinus infection) (Beyond the Basics),” UptoDate, July 18, 2019 Zara Patel, Peter Hwang, “Uncomplicated acute sinusitis and rhinosinusitis in adults: Treatment,” UptoDate, September 25, 2020