What Causes A Sinus Infection?

woman with sinus infectionA sinus infection is an inflammation of the lining of the sinus passages that can cause cold-like symptoms that get worse over time. As the passage of air becomes blocked, the sinuses can be filled with fluid, bacteria, and germs that can eventually lead to an infection.

Most cases of sinusitis are acute, which last anywhere from three weeks to two months.  If your sinusitis lasts longer than two months, you may have chronic sinusitis.  Whether you are suffering from chronic or acute sinusitis, the symptoms will often be the same.

Symptoms of a Sinus Infection

  • Nasal Discharge – During a sinus infection, you will notice a lot of discharge that will either be yellow or green in color and is indicative of an infection.
  • Pain and Pressure in the Face – Sinusitis can cause pressure and pain along the nasal passages and through the forehead area.
  • Headache – The pressure building up can cause a sinus headache that is not often alleviated with mild pain relievers.
  • Congestion – You will not only experience nasal congestion, but possibly congestion in your chest as well.
  • Fever – A fever of 101 degrees or higher often indicates that an infection is present.
  • Sore or Scratchy Throat – You may experience a sore or scratchy throat due to discharge from your sinuses.
  • Cough – Congestion in your chest may be accompanied by a cough.
  • Pain or Pressure in the Ear Canal – Due to the pressure on your sinuses, you may feel blockage or pain along your ear canal.
  • Dental Pain – Swollen sinuses can often cause nerve pain along teeth or your jawline.
  • Lack of Smell or Taste – Nasal congestion can cause a lack of smell and you may also notice a lack of taste, or even bad breath.

What Causes a Sinus Infection?

Not only can the symptoms of a sinus infection vary, but the causes can come from a variety of sources as well.  It is extremely important to determine what the cause of the sinus infection is in order to determine the most appropriate form of treatment.  Below is a list of sinus infection causes.


One of the most common causes of a sinus infection is a virus.  Sinusitis can occur in response to a virus and sometimes can start as a cold.  The virus can cause the lining of the nasal passages to become inflamed resulting in an infection.  This infection can continue even after the primary respiratory symptoms have resolved.


Bacteria can be the cause of a sinus infection, but can also occur as a secondary result from a viral infection.  Once the nasal passages swell, the fluid that becomes blocked in the sinuses can grow bacteria resulting in a bacterial infection.


Fungus is becoming a more common culprit in cases of chronic sinusitis and is typically treatable and mild in those with normal immune systems.  The infection is caused by fungi of typically the Aspergillus or Mucor species which enter the sinuses and cause a grease-like build-up throughout.


Another common cause of sinusitis is allergies.  Exposure to allergens can cause the inflammation of your nasal passages to become inflamed and swollen leading to blockage.

Tooth Infections

Since the upper part of your teeth lies directly below the maxillary sinus, it is possible for a tooth infection to erupt into the sinuses above, spreading the infection into your sinus cavities.

Nasal Polyps

Nasal Polyps are growths inside of the nasal cavity.  While the direct cause is not known, people who suffer from asthma or allergies are more likely to develop nasal polyps.  They can vary in size and become large enough to block nasal passages and trap fluid and debris in the nasal cavity, resulting in sinusitis.

Deviated Septum

Structural abnormalities such as a deviated septum can create blockages or cause more chronic inflammation which can result in sinus infections.

Deterring the cause of your sinus infection will be directly related to the treatment options that will be recommended.

Treatment Options for Sinus Infections

For infections caused by viruses, treatment may include:

  • Saline Washes
  • Steam or Vaporizers
  • Decongestion Nasal Spray

For sinusitis caused by allergies your doctor may recommend:

  • Antihistamines
  • Nasal Corticosteroids

If bacteria are the culprit, a round of antibiotics will be prescribed.

For those who suffer from a sinus infection caused by structural abnormalities, such as a deviated septum or nasal polyps, surgery may be advised to correct the structure or remove the polyp.

If you suffer from chronic or acute sinusitis, it is important to get a proper diagnose.  Contact the ENT Specialists at New York ENT today to determine the cause of your sinus infection and help get yourself on the road to recovery.

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