Adult Sinusitis

Berrylin J. Ferguson, MD
Sarah K. Wise, MD

“Sinusitis” and “sinus infection” are terms that are commonly used by patients, healthcare providers, and the media.  However, accurately diagnosing sinusitis is often more complicated than many people realize.  A number of factors are considered before the correct diagnosis can be made.  These include a patient’s symptoms, the time course of the symptoms, and often the results of additional tests.

We have included some definitions below help you understand sinusitis, as well as some other processes that may mimic sinusitis.

Sinusitis, or rhinosinusitis, results from inflammation of the lining of the nasal passages and paranasal sinuses.  The paranasal sinuses are air spaces that fill your cheeks, forehead, and areas between your eyes.  While the bones of the face and forehead may feel solid, they are actually hollow.  The hollow spaces are the sinuses.  The anatomy of the sinuses and inflammation that occurs with sinusitis helps to explain many of the symptoms that are experienced with sinusitis and similar disease processes.  The term “inflammation” refers to irritation and swelling in the sinuses.

Some symptoms are very common with sinusitis.  Other symptoms occur less frequently.  In addition, many symptoms that occur with sinusitis or sinus infections may also be seen with other nasal and sinus conditions.  For example, viral upper respiratory infections (the common cold) or nasal allergies can lead to similar symptoms.  This often leads to confusion.  Your Otolaryngologist (ENT physician) can help you in determining the correct diagnosis and prescribing appropriate treatment for your condition.


  • Nasal obstruction or nasal congestion
  • Thick & discolored drainage
  • Decreased smell or taste
  • Facial pain or pressure
  • Facial pressure or fullness
  • Headache
  • Fatigue
  • Bad breath
  • Fever
  • Upper tooth pain
  • Cough
  • Ear pressure
As many of these symptoms may overlap with other nasal and sinus conditions, the time course, specific combination of your symptoms, and other tests may also help to determine the correct diagnosis for your problem.  These items are addressed in the following sections.

One to two weeks: Inflammation of the paranasal sinuses that is present for less than a week or two is usually due to a viral infection, also known as a viral upper respiratory infection or the common cold.  Some symptoms are commonly associated with viral upper respiratory infections but not frequently seen with bacterial sinus infections.  These include fever, fatigue, sore throat, and muscle aches.  Because this type of infection is typically caused by a virus, antibiotics are not recommended.  Antibiotics will not speed the resolution of the infection, since antibiotics do not stop viruses from growing.  In the case of viral upper respiratory infection, typical recommendations include rest, drinking plenty of fluids, and treating symptoms with appropriate over-the-counter medications as directed by your physician.  We are exposed to airborne viruses frequently, and healthy adults may get a few viral infections per year.  Children and adults exposed to young children often have more viral upper respiratory infections.

If your symptoms do not improve as you reach 10 to 14 days, you may be suffering from acute sinusitis.

More than Two Weeks:  Symptoms present for more than 2 weeks without improvement may be due to an acute sinus infection.  This often occurs following a cold or a particularly bad allergy season (in a patient with environmental allergies).  It is important to make this diagnosis because antibiotics, if chosen correctly, will speed resolution of symptoms.

More than a Few Months:  If your symptoms have been going on for longer than several months, then it is frequently the case that bacterial infection is NOT the cause of the inflammation. In long standing cases of sinusitis, also known as chronic sinusitis, non-infectious processes are often the cause.  For example, patients with chronic sinusitis may have nasal polyps or chronic swelling of the sinus lining.  These types of problems often accompany asthma.  It is common for patients with chronic sinusitis to have symptoms that are intermittently worse or better, but patients typically have some degree of symptoms at all times.

Nasal Endoscopy:  When visiting your Otolaryngologist (ENT), it may be recommended that you undergo a “nasal endoscopy”.  This is a procedure performed in the physician’s office.  No sedation or general anesthesia is required for the procedure.  Typically, a spray will be applied to your nose to make the endoscopy more comfortable for you.  The spray will often contain a decongestant and a topical anesthetic medication.  The decongestant helps to shrink the nasal lining to allow the scope to pass more easily and the anesthetic numbs your nasal lining. 

The scope used for a nasal endoscopy is a lighted tube that allows the structures in the nose and sinuses to be seen more easily than by simply looking into the front of the nostrils.  Nasal endoscopes can help your Otolaryngologist seen the anatomy of your nose, the degree of swelling of the nasal/sinus lining, mucus drainage coming from the sinus cavities, and nasal polyps (See Figure, dark arrows) or other findings. Further, the nasal endoscopy procedure also allows your physician to take appropriate cultures from any mucus drainage that is seen.  This can help guide the antibiotics that are chosen to treat your sinus infection and is a dependable method for diagnosing the bacteria responsible for an infection.  Cultures taken at random from the front of the nose or from blowing the nose are not reliable and should not be used to guide antibiotic choices.  If necessary, biopsies and other indicated procedures can also be performed via nasal endoscopy in the Otolaryngologist’s office.

X-Rays: While X-rays were used in the past to image the sinuses, plain X-rays are no longer routinely performed for the diagnosis of sinusitis.  In our current medical armamentarium, a CT (CAT) scan is the study of choice for diseases of the paranasal sinuses.

CT scan: Radiologic studies are not routinely performed for the initial diagnosis or treatment of sinus infections, but your physician may recommend a CT scan of the sinuses in certain cases.   After treatment of sinusitis with antibiotics or other medications, it is common for your physician to obtain a CT scan of the sinuses to evaluate the effectiveness of the medicines in clearing the sinus infection and to determine if any additional therapy is recommended.  In addition, if the disease presentation is unclear or does not fit usual symptom patterns, a CT may be obtained to better guide therapy.  Finally, if more serious complications of a sinus infection are suspected, such as spread to the orbits (eye sockets) or brain, a CT scan may be obtained for diagnosis.

Figure Legend: Ethmoid sinus (white arrow). Maxillary sinus (asterisk)

MRI scan: MRI scans are not typically ordered for sinusitis.

Limitations of radiologic studies:  While CT scans can be helpful in diagnosing sinus problems and helping to guide treatment, any radiologic study is simply a picture taken at one time.  Symptom can change over time, and this  may lead your physician to recommend additional studies at a later time.  Further, the sinus abnormalities seen on CT scan in cases of viral upper respiratory infection are no different than those seen for bacterial sinusitis.  For this reason, the diagnosis and treatment of these early stage infections are typically based on symptom complex and time course, rather than imaging studies.

Viral Upper Respiratory Infection or Common Cold: While many of the symptoms of a viral cold are the same as bacterial sinusitis, these processes are treated differently.  See the section above entitled TIME COURSE – ONE TO TWO WEEKS.

Environmental Allergies: The symptoms of environmental allergies and sinusitis overlap to some degree.  In addition, some patients may have both allergies and sinusitis.  Some symptoms that are more common with environmental allergies (and less common with sinusitis) include sneezing, clear nasal drainage, itchy nose or throat, itchy watery eyes, itchy skin, and eczema.  In addition, allergy symptoms tend to fluctuate with the seasons or with a change in your environment, such as going from indoors to outdoors.  Most people with allergies will notice specific triggers for their symptoms like increases in the pollen count or coming into contact with a cat or dog.

Headaches:  “Sinus headache” is a common term, but can be misleading.  Facial pain/pressure or headache in the absence of nasal congestion or discolored drainage is only rarely associated with true sinusitis.  There are many causes of headaches and facial pain.  These include migraine headaches, tension headaches, temporomandibular joint (TMJ or jaw joint) problems, and dental issues, as well as rarer causes of headaches like tumors.  Your physician can help you determine the best evaluation and treatment for your headache.

Acid Reflux: Acid reflux (stomach acid coming up to irritate the esophagus or throat) may contribute to a number of symptoms that are commonly associated with sinusitis.  These include thick phlegm in the throat, post-nasal drainage, chronic throat clearing, and intermittent voice changes.  Acid reflux is treated differently than sinusitis, so it is important to make the appropriate diagnosis and begin appropriate treatment for your condition.

In rare cases, sinus infections may spread outside the confines of the sinus cavities.  The orbits (eye sockets) and brain are located close to the sinus cavities and may be involved with sinus infections in very rare cases.  If you experience any of the symptoms below in association with a sinus infection, you should seek medical attention immediately.
  • Severe, unrelenting headache
  • Stiff neck
  • Confusion
  • High fever
  • Double vision (or other vision changes)
  • Swelling or redness of the eye or eyelids

We have presented the most common symptoms, time course, and diagnostic tests for sinusitis.  However, please remember that every patient is different.  In certain cases, sinus infections do not follow the typical course or symptom presentation.  If you are uncertain about your particular sinus problem, please consult with your physician.

Revised 6/2011
©American Rhinologic Society