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When reading about sinusitis, or talking to your doctor or pharmacist about it, all the different terminology can be confusing. Not understanding what may be causing your sinusitis and the sinus congestion that comes with it can also make it difficult to know what to do about it.

The good news is that some treatments can be used effectively even if you don’t know what kind of sinusitis you have or why. This is because they treat the symptoms rather than the cause,1 and that can help you recover! But it is important, when possible, to try and identify the cause of your sinusitis as this may affect some elements of your treatment.1,2 For example, there is no point in taking an antibiotic if you have viral sinusitis, because antibiotics have no effect on viruses.

Here we explain some of the terms and definitions to make it a little easier for you.


What is the difference between sinusitis and sinus congestion?

Sinusitis is the condition causing the symptom of sinus congestion.3,4 Sinus congestion is the blocked-up, stuffy feeling you get when you have sinusitis and you struggle to clear the mucus out of your nose and sinuses.6


What is the difference between sinusitis, rhinitis and rhinosinusitis?

Sometimes, when you ask your doctor or pharmacist about your sinus congestion, they refer to ‘rhinosinusitis’ instead of ‘sinusitis’.

In ‘Understanding the sinuses and sinus congestion’ we explained that sinusitis is an inflammation and malfunctioning of the mucous layer in the paranasal sinuses, leading to sinus congestion.1 Rhinitis refers to the same problem, but occurring in the nasal passages, leading to nasal congestion.5

Rhinosinusitis means that this inflammation and malfunctioning of the mucous layer is happening in the nasal passages and the sinuses at the same time, leading to both nasal and sinus congestion.7


Historically, it was thought that sinusitis, rhinitis and rhinosinusitis were three separate conditions, but the modern understanding is that they are actually intricately linked.4 This is because we now know that:     

  • the nasal passages and the sinus cavities have many similarities and the mucous lining between them is continuous4     
  • when one part of the lining is affected by a common cold, the other part is too4     
  • sinusitis usually starts as rhinitis in the nasal passages and then becomes sinusitis in the paranasal sinuses.4

This means that the clinical condition often referred to as ‘sinusitis’ is in fact ‘rhinosinusitis’,2,4,5 which is why your doctor or pharmacist may use that term when referring to your condition.

For the sake of clarity, this website uses ‘sinusitis’ as this is the familiar term for most people.


What is the difference between acute and chronic sinusitis?

In adults, acute sinusitis usually comes on suddenly,4 with symptoms lasting less than eight weeks in children and less than 12 weeks in adults.2 Chronic sinusitis is only diagnosed if you have had symptoms for 12 weeks or more.4

What is the difference between viral and bacterial sinusitis?

There are many possible causes of sinusitis,3 with the most common being a virus.1,8 Approximately 0.5-2% of viral upper respiratory tract infections ultimately become a combination of viral and bacterial sinusitis.1 Both may be contagious.

Identifying whether your sinusitis is caused by bacteria or a virus may affect some elements of your treatment. As already mentioned, there is no point in taking an antibiotic if you have viral sinusitis, because antibiotics have no effect on viruses, but other treatments can be used even if you don’t know the cause, as they treat the symptoms instead.1

Even doctors may find it difficult to work out4,8 whether sinusitis is caused by bacteria, a virus or something else (like allergies or cigarette smoke), but some indications that sinusitis may be bacterial include:1     

  • symptoms that are severe at the beginning of the infection 
  • fever (although a fever in a child may be the result of either a viral or bacterial infection)    
  • moderate to severe facial or dental pain    
  • sinuses on one side of the face being tender when pressed     
  • swelling around the eyes     
  • symptoms that get significantly worse after three to five days     
  • symptoms that do not improve after seven to 10 days.

Can the colour of the discharge coming from my nose and/or sinuses tell me whether I have a viral or bacterial infection?

Unfortunately not. Cloudy, brown, green or yellow discoloured mucus may be present in both bacterial and viral sinusitis.1 Colour may therefore be a weak indicator of what may be causing your sinusitis9 and of whether your sinusitis is infectious or not.

  1. BMJ Best Practice. Acute sinusitus. Last updated: 01 Mar 2019. Available at: Last accessed May 2019.
  2. Hallet R and Naguwa SM. Severe rhinosinusitis. Clin Rev Allergy Immunol 2003; 25:177-190.
  3. Ah-See KW and Evans AS. Sinusitis and its management. BMJ 2007; 334:358-361.
  4. Lanza DC and Kennedy DW. Adult rhinosinusitis defined. Supplement to Otolaryngol Head Neck Surg 1997; 117(3.2):S1-S7.
  5. Lau J et al. Diagnosis and treatment of acute bacterial rhinosinusitis: summary. In: Agency for Healthcare Researchand Quality (US) 1999. Available at: Last accessed May 2019.
  6. Mayo Clinic. Chronic sinusitis. Available at: Last accessed May 2019.
  7. Rosenfeld RM et al. Clinical practice guidelines (update): adult sinusitis. Otolaryngol Head Neck Surg2015; 152(2S):S1-S39.
  8. Scheid DC and Hamm RM. Acute bacterial rhinosinusitis in adults: part 1. Evaluation. Am Fam Physician; 70(9):1685-1692.
  9. Gonzales R et al. Principles of appropriate antibiotic use for treatment of nonspecific upper respiratory tract infectionsin adults: background. Clinical Practice Guideline, Part 2. Ann Intern Med 2001; 134:490-494.