1. Sinusitis (Sinus Infection) Slideshow Pictures
2. Nasal Allergy Relief Products Slideshow Pictures
3. 10 Common Allergy Triggers Slideshow Pictures

Medical Author:

Charles Patrick Davis, MD, PhD

Charles Patrick Davis, MD, PhD

Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.

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Medical Editor:

William C. Shiel Jr., MD, FACP, FACR

William C. Shiel Jr., MD, FACP, FACR

Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.

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In this Article

• Sinus infection facts
• What is a sinus?
• What is a sinus infection?
• What causes sinus infections?
• What are the types of sinusitis?
• What are the signs and symptoms of sinus infection?
• How is sinus infection diagnosed?
• How is sinus infection treated?
• Are there home remedies for a sinus infection?
• What are complications of sinus infection?
• Can sinus infection be prevented?
• Pictures of Sinusitis (Sinus Infection) - Slideshow
• Pictures of Nasal Allergy Relief Products - Slideshow
• Pictures of 10 Common Allergy Triggers - Slideshow
• Patient Comments: Sinus Infection - Symptoms
• Patient Comments: Sinus Infection - Causes
• Patient Comments: Sinus Infection - Home Remedies
• Patient Comments: Sinus Infection - Complications
• Patient Comments: Sinus Infection - Effective Treatments
• Find a local Ear, Nose, & Throat Doctor in your town
• Sinusitis Index

Sinus infection may be caused by anything that interferes with airflow into the sinuses and the drainage of mucus out of the sinuses. The sinus openings (ostea) may be blocked by swelling of the tissue lining and adjacent nasal passage tissue, for example with common colds, allergies, and tissue irritants such as OTC nasal sprays, cocaine, and cigarette smoke. Sinuses can also become blocked by tumors or growths that are near the sinus openings.

The drainage of mucous from the sinuses can also be impaired by thickening of the mucous secretions, by decrease in hydration (water content) of the mucous brought on by disease (for example, cystic fibrosis), drying medications (antihistamines), and lack of sufficient humidity in the air. The epithelial cells have small hairlike fibers, called cilia, which move back and forth to help the mucus move out of the sinuses. These small cilia may be damaged by many irritants, especially smoke. This can prevent them from assisting the mucus in draining from the sinuses.

Stagnated mucus provides an environment for bacteria, viruses and in some circumstances (for example, AIDS or immunodepressed persons) fungus to grow within the sinus cavities. In addition, the microbes themselves can initiate and exacerbate sinus blockage. The most commonly infected sinuses are the maxillary and ethmoid sinuses.

Rarely, immunodepressed or victims of multiple traumas in disasters such as tsunamis, hurricanes, earthquakes, or tornadoes may breathe in fungi from the soil or water. Eventually, in a few days to over a week, the fungi can grow and cut off blood supply to almost any type of tissue, especially in the nose and eyes. These infections, although rare, are serious and can be deadly and require immediate medical and surgical care. Although the fungal infection may resemble common bacterial sinusitis initially, it is a disease termed zygomycosis or mucormycosis.