Causes of Sinusitis and Sinus Infections - NY Otolaryngology Group

Causes of Sinusitis

The following are the most common causes of sinusitis or sinus infections. It is important to understand that you may be affected by more than one cause.


Mayo Clinic scientists have determined that inhaled fungus and mold trapped in the nasal mucus is one of the major causes of sinusitis. Regular cleansing of the nasal and sinus passages washes away mucus and its trapped inhalants.

Acid Reflux

Reflux of stomach acid into the throat and nose is one of the most common underlying causes of sinusitis. This type of acid reflux often occurs without heartburn or indigestion, which would otherwise alert a patient to the condition. Many who experience reflux also experience heavy postnasal drip and sometimes a choking sensation. Dietary and lifestyle changes can reduce reflux and, therefore, improve some sinus problems. Elevating the head of the bed is helpful in reducing nighttime symptoms of acid reflux, such as coughing and choking. Patients are also advised not to eat within three hours prior to bedtime to further reduce the causes of acid reflux.

When medication is needed to help decrease the production of acid in the stomach, proton pump inhibitors (Nexium, Protonix, Prilosec, Prevacid, Zegerid, Omeprazole and Aciphex) and/or H2 blockers (Zantac, Axid, Pepcid, and Tagamet) are often prescribed.


Reflux causing foods such as fried foods and those high in fat and caffeine can trigger sinus symptoms, as can chocolate, tomatoes, onions, mint and excessive alcohol.


Cigarette smoke is a toxic substance that increases the production of stomach acid, possibly resulting in acid reflux. It is a direct irritant of the nasal and sinus linings and affects the normal activity of the mucus membranes.


Environmental allergy can be a major factor contributing to chronic sinusitis. While many people experience seasonal symptoms, such as sneezing, itching and runny eyes, others may have more subtle year-round symptoms making diagnosis more difficult. Accurate allergy diagnosis requires a thorough medical history review as well as blood work and often skin reaction testing. Successful treatment depends on identifying the precise offending allergens so they can be avoided and, when necessary, medical treatment such as antihistamines, nasal sprays, and desensitizing allergy shots.

Immune Disorders

Immune disorders, including the inability to manufacture antibodies properly, are occasionally a cause of chronic sinusitis. Diagnosis requires taking a complete medical history, blood work, and, sometimes, checking the patient’s ability to make antibodies after being vaccinated. Treatment may include intravenous gamma globulin antibody therapy.


Asthma and sinusitis are both considered “reactive airway diseases.” Coughing and wheezing frequently accompany sinusitis, even in patients with no previous asthmatic history. Many patients note a decrease in asthma symptoms and the lessened need for asthma medication following the successful treatment of their sinusitis.