9 Symptoms of a Sinus Infection (& What to Do)

Symptoms of s sinus infection (also known as sinusitis or rhinosinusitis) emerge when the lining of the sinuses in the face become inflamed. Sinuses are hollow spaces that are found surrounding the nasal cavity. With sinus infections, it is common to have facial pain, nasal discharge and a headache (although symptoms can vary depending on the cause of the infection or on the person's health status or sensitivity.

You may be able to confirm the presence of pediatric sinusitis (sinus infections that occur in babies and children), if nasal discharge is also accompanied by signs like irritability, fever, drowsiness, difficulty breastfeeding or resistance to eating (especially foods the child usually likes).

If you suspect you have a sinus infection, report your symptoms below to see what you should do:

  1. 1. Bad breath
  2. 2. Yellow or greenish nasal discharge
  3. 3. Cough that gets worse at night
  4. 4. Loss of smell
  5. 5. Pain in the face, especially around the eyes or nose
  6. 6. Constant headache
  7. 7. Feeling of heaviness in the face or head, especially when bending down
  8. 8. Nasal congestion
  9. 9. Fever above 38º C (or 100.4º F)

How to identify different types

Inflammation in the sinuses can be caused by several things, like:

1. Viral infection

A viral infection, usually the common cold, causes sinusitis in the majority of sinus infection cases (about 80%). Sinusitis will typically develop in people who present with nasal discharge (which can range from clear to yellow or green). 

This type of sinus infection is associated with more mild or tolerable symptoms, and fever usually does not surpass 38ºC (or 100.4ºF). A viral sinus infection can also emerge with other viral-like symptoms, like a sore throat, swollen eyes, sneezing and a stuffy nose.

2. Allergies

A sinus infection caused by allergies can present very similarly to an infection caused by a virus. Inflammation can occur due to an allergy flare-up or with exposure to specific situations (e.g. exposure to intense cold, dry environment, or musty clothes or books).

It is normal to have a sinus infection with other allergy-related symptoms, like itchy nose and throat, frequent sneezing and red eyes.

3. Bacterial infection

Sinus inflammation caused by a bacterial infection occurs in about 2% of cases. It is usually suspected when symptoms like high fever (over 38.5ºC or 101.3ºF), intense facial pain, and thick nasal or throat mucus emerge. Bacterial infections can also be suspected if even milder symptoms last for over 10 days. 

4. Fungal infection

A fungal sinus infection usually happens in cases of persistent or chronic sinusitis that don't go away with treatment. A common symptom of this type of sinusitis is pain localized to one area of the face. Symptoms like nasal discharge and fever do not usually occur with fungal infections. 

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Through clinical and physical examination, the doctor can usually pinpoint the type of sinus infection occurring, but this can be difficult given they all present very similarly.

There are other causes of sinus inflammation that are more rare, like tumors, polyps, trauma or chemical irritation. These causes should be investigated by the doctor if the patient is at risk for these situations,

How a diagnosis is confirmed

To diagnose a sinus infection, a clinical exam by a family doctor, pediatrician or ENT is all that is necessary. Testing through bloodwork or imaging are not required, but they can be helpful to rule out another diagnosis or to determine the origin of the inflammation.

Sinusitis can be classified by how long the infection occurs for, for example:

  • Acute, which lasts up to 4 weeks
  • Sub-acute, which lasts between 4 and 12 weeks
  • Chronic, which lasts for longer than 12 weeks due to resistant microorganisms; it can last for several years

Acute sinusitis is the most common type. Sub-acute and chronic sinusitis can occur to people with a history of antibiotic-resistant bacteria (e.g. from prolonged use of the wrong medication, or following admission to the hospital or a surgery).

Chronic sinusitis can also occur in people who have a tendency to accumulate discharge in the sinuses due to abnormalities in the lining or due to illnesses that produce excess mucus (like cystic fibrosis).

What to do if you get a sinus infection

If you have symptoms of a sinus infection that are additionally presenting with fever, thick nasal discharge and intense facial pain, you should consult a doctor to ENT for assessment and treatment.

Generally, if you only have cold symptoms, or symptoms that improve within 7 to 10 days, you likely have a viral sinus infection or allergy-related infection. You should use medication that will alleviate symptoms. These medications include analgesics, anti-inflammatories or corticosteroids.

If any of your symptoms are severe, like a high-grade fever, or if they don't improve within 10 days, antibiotics (e.g. amoxicillin) prescribed by your doctor may be necessary.