What is Sinusitis (Sinus Infection)?

A sinus illustration overlay of a woman with sinus pain.

Sinus Pain Attack!

Sinus problems and sinus-related symptoms are common reasons people see their doctors. Symptoms include pain in the forehead or between the eyes, toothache, feeling of fullness in the mid-face, stuffy nose, and congestion.

CT scan showing normal sinuses.

What Are Sinuses?

Your sinuses are air spaces in your skull and facial bones that make up the upper part of your respiratory tract from your nose into your throat. The sinuses are in your forehead (frontal sinuses), inside your cheekbones (maxillary sinuses), and behind the nose (ethmoid and sphenoid sinuses).

Cilia lining of the sinus cavity mucus membrane.

What Is Sinusitis?

Inflammation of the tissues lining the sinuses is called sinusitis. Infections with viruses or bacteria or allergies cause the majority of cases of sinusitis.

A close up of nostrils breathing in rhinovirus and pollen spores.

It May Start as a Cold

Most cases of sinusitis start off with the inflammation from a virus such as the common cold. This inflammation can lead to bacterial colonization and cause a bacterial sinus infection.

Woman with painful sinus pressure.

Sinusitis Symptoms

Pressure and pain in the sinuses (in different areas of the face or behind the eyes) are the main symptoms of sinusitis. More severe infections may lead to a yellow or green discharge from the nose, sore throat, headache, fever, and an overall feeling of fatigue.

MRI of inflammation within the sinus cavity.

Chronic Sinusitis

Chronic sinusitis is defined as inflammation of the sinuses that lasts for more than three months. It is characterized as chronic sinusitis with or without polyposis. Chronic sinusitis may be caused by allergies, abnormal sinus anatomy that leads to chronic blockage (polyps), or dental problems.

Anterior rhinoscopy showing nasal polyps.

Nasal Polyps

Nasal polyps are an overgrowth of tissue within the sinuses that can block the flow of mucus and air.

Man using nasal decongestant spray for sinus relief.

Nasal Decongestants

Nasal sprays and nasal decongestants can be used for relief of the symptoms of acute sinusitis. These medications help shrink the inflamed tissue and allow secretions and air to pass through more easily. Over-the-counter nasal spray decongestants should only be used for a maximum of three days. After this, the tissues can become more inflamed and lead to a disorder called rhinitis medicamentosa. Consult your doctor before using any drugs to treat your sinusitis. Combinations of oral medications and nasal anti-inflammatories may be better options to treat your sinusitis.

Illustration of the human rhinovirus responsible for the common cold.

Antibiotics Usually Unnecessary

Most cases of sinusitis are triggered by viruses such as the common cold virus or rhinovirus (pictured). Sinus inflammation triggered by viruses does not respond to antibiotics. Antibiotics should only be used in cases of sinusitis where a bacteria pathogen is suspected by your doctor or documented by a culture of the mucus from your sinuses.

Woman using a sinus rinse system to help clear sinus symptoms.

Treating Allergy-Related Sinusitis

Home remedies can help relieve some symptoms of sinusitis. Irrigation of the sinuses with a Neti-pot or squeeze bottle, or breathing in warm humidified air can help decrease symptoms of sinusitis. If symptoms are due to allergies, over-the-counter antihistamines may help.

Photo of a child with runny nose.

When to Visit the Doctor

If your sinusitis symptoms include the following, see your doctor immediately: fever, headache, change in vision or double vision, swollen eye socket, neck stiffness, severe sore throat, and a yellow or green mucus discharge. If you have any concerns or are unsure about your condition, contact your doctor.

A doctor using an endoscope in the nasal cavity of patient.

Chronic Sinusitis Treatment Still a Puzzle

Chronic sinusitis is often difficult to treat. There are many factors that can lead to chronic inflammation of your sinus passages, and eliminating these factors is the first step in treatment of chronic sinusitis. Long-term medications or even surgery may be necessary to control and treat symptoms.

An X-ray of a patient with acute sinusitis.

Sinusitis Complications

Sinusitis can become bad enough to cause serious medical complications. Infections can spread around the eye, into the middle ear, and even around the brain (meningitis).

A man breathing through his nose.

Sinusitis Prevention

You may not be able to completely avoid getting sinusitis, but there are ways to prevent it in some cases:

  • Do not smoke
  • Avoid dry environments
  • Use a humidifier when needed
  • Drink plenty of fluids
  • Seek treatment for chronic allergies that can trigger sinus inflammation



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  • American Academy of Allergy, Asthma & Immunology: "Sinusitis: Tips to Remember"
  • WebMD Image Collection: "Sinuses (Human Anatomy)"
  • WebMD Medical Reference: "An Overview of Sinusits"
  • WebMD Medical Reference: "Nasal Polyps"
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