Sinusitis – Diagnosis, Symptoms and Treatment

Medically Reviewed by Dr. Po-Chang Hsu, MD, MS

Medically reviewed by Dr. Po-Chang Hsu, MD, MS

Medical Professional

Updated - January 25, 2021

Dr. Po-Chang Hsu is a medical doctor from Tufts University in Boston, Massachusetts, interested in pediatrics and neonatology.

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What is Sinusitis?

Sinusitis is a medical condition characterized by inflammation of the sinuses and nasal passages.  This typically results in a runny nose, nasal congestion, sneezing, postnasal drip, headache, and occasionally fever.  Allergies or infections usually cause rhinosinusitis due to viruses or bacteria.  The condition can begin with a viral infection then result in a bacterial superinfection.  This is a common occurrence called "double sickening."

It can be difficult to tell whether viruses or bacteria cause symptoms. This is important because bacterial sinus infections warrant treatment with antibiotics.  Due to this condition's importance, patients must understand its causes, symptoms, and treatment.

What Causes Sinusitis?

Allergies, viruses, or bacteria typically cause sinusitis.

Allergens usually cause allergic rhinitis in the environment, such as:

  •         Pollen
  •         Grass
  •         Pet dander
  •         Dust mites
  •         Insects (cockroaches)
  •         Mold

This may occur during a particular season (e.g., spring), in specific environments (e.g., home or work), or through exposure to pets.

Allergens, viruses, and bacteria enter the nasal passage and promote the release of histamine.  Histamine is a molecule that promotes inflammation and mucous secretion, resulting in swelling of the nasal passages and nasal congestion.

How Common is Sinusitis?

Sinusitis is a common condition that is frequently evaluated in the primary care clinic.  The incidence of acute sinusitis is approximately 15-40 episodes per 1000 patients per year.  About 0.5% of upper respiratory infections are complicated by sinusitis.

Severe or complicated cases of this disease may require referral to an ear, nose, and throat specialist (otolaryngologist) or allergist.

Signs and Symptoms

Symptoms of sinusitis often include:

  •         Runny nose
  •         Nasal congestion
  •         Headache
  •         Sneezing & nasal itching
  •         Postnasal drip
  •         Throat clearing & cough
  •         Loss of smell (anosmia)

Patients may have swollen nasal passages and clear or purulent mucous drainage from the nose.  A clear discharge may occur with allergies or viruses, but purulent drainage is often yellow or green, which indicates a bacterial infection.  People with allergies also tend to have other symptoms, such as eye allergies (allergic conjunctivitis), asthma, and hives (allergic rash).

Viral sinusitis generally lasts no longer than 1-2 weeks.  It may be associated with a sore throat, body aches, diarrhea, and other flu-like symptoms.

Bacterial sinusitis is classically characterized by a headache that worsens with leaning forward – due to increased sinus pressure.  It may also produce a sensation that is very similar to a tooth cavity affecting the molars.  Fever is common with bacterial sinusitis as well, although it may also occur with viral rhinosinusitis.  The bacterial infection should be suspected if symptoms do not improve with conservative measures or last longer than 1-2 weeks.


Sinusitis is a clinical diagnosis, meaning your doctor can diagnose it based on your symptoms and signs on physical examination.  There are no specific tests to make a diagnosis.

Your doctor will typically press on your sinuses to evaluate for pain or pressure.  They will also look inside your ear canals to ensure no signs of inflammation or infection.  Your doctor will often look inside the nasal passage with an otoscope to evaluate the turbinates and check for swelling or purulent discharge.  They will also examine the oral cavity and throat, looking for inflammation or pus.  If they are concerned about pneumonia, they may listen for abnormal sounds in the lungs.

Your doctor may occasionally obtain a CT scan of your sinuses to confirm the diagnosis.

Sinusitis Medication

The treatment of sinusitis depends on whether the symptoms are due to allergies, viruses, or bacteria.  Some treatment overlaps between these three causes.

Allergic rhinitis

The first-line treatment of allergic rhinitis is a class of intranasal corticosteroids, which work by reducing inflammation.  The most common intranasal corticosteroids include:

These medications can start working within hours, but their maximal effectiveness occurs after 1-2 weeks of daily or twice-daily use.

An alternative to intranasal corticosteroids is intranasal antihistamines.  The most common intranasal antihistamine is  Astelin (Azelastine).  Histamine released in the nasal passages promotes inflammation.  Therefore, intranasal antihistamines reduce histamine's ability to start the inflammatory process, thereby decreasing nasal inflammation and symptoms of allergic rhinitis.

In addition to intranasal medications, individuals with allergic rhinitis may benefit from oral antihistamines.  These include:

Oral antihistamines are frequently combined with intranasal corticosteroids if corticosteroids are not effective enough in reducing symptoms.

Viral sinusitis

If your symptoms are due to viral sinusitis, your doctor will typically recommend that you rest and drink plenty of fluids, usually at least 1.5-2L daily.  They may also recommend the following medications for your symptoms:

Tylenol (acetaminophen) or NSAIDs (e.g., Advil, Naprosyn) for a sore throat, headache, body aches, and fever or chills.

Decongestant nasal sprays such as Afrin (phenylephrine) or Sinex (oxymetazoline) for a runny nose or nasal congestions.  They may also recommend oral decongestants such as Sudafed (pseudoephedrine) – this should be avoided in patients with heart disease.

Viral sinusitis typically lasts about 1-2 weeks.

Bacterial rhinosinusitis

If your symptoms persist longer than 1-2 weeks or are accompanied by a purulent nasal discharge (green/yellow pus), significant headache, and fever, you may have bacterial sinusitis.  This requires treatment with antibiotics such as:

Nasal corticosteroids and decongestants may also be beneficial to treat symptoms.  Your doctor will also often recommend a Neti pot – this device provides saline irrigation of the nasal passages and sinuses, helping eliminate allergens, viruses, and bacteria.


  1.     Chow AW, Benninger MS, Brook I, et al. IDSA clinical practice guideline for acute bacterial rhinosinusitis in children and adults. Clin Infect Dis 2012; 54:e72. -
  2.     Rosenfeld RM, Piccirillo JF, Chandrasekhar SS, et al. Clinical practice guideline (update): adult sinusitis. Otolaryngol Head Neck Surg 2015; 152:S1. -

The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.