How Can You Tell if You Have a Sinus Infection?

What is a sinus infection?

You can tell you have a sinus infection from an uncomfortable full or feeling of pressure in your face, stuffy nose and face, postnasal drip, cough, and low-grade fever.
You can tell you have a sinus infection from an uncomfortable full or feeling of pressure in your face, stuffy nose and face, postnasal drip, cough, and low-grade fever.

A sinus infection happens when your sinuses become inflamed. It’s also known as sinusitis. Your sinuses are in the bones behind your cheeks, jaw, and eyebrows. They make mucus which cleans out the bacteria and other particles from the air you breath. Sinus infections are usually caused by bacteria or virus, but there can be other problems causing it.

When your sinuses are infected your mucus has nowhere to drain and will stay in your swollen cavities, becoming painful. There may be drainage in your throat, called postnasal drip, that causes a sore throat. There are multiple types of sinus infections, and the most common type is caused by a cold that turns into a bacterial infection.

Most sinus infections will go away on their own or with treatment at home. But if your sinus infection becomes more severe or is persistent, you will want to see a doctor for proper diagnosis and treatment.

Signs and symptoms of sinus infection

An uncomfortable full or feeling of pressure in your face is an easily identifiable symptom of sinus infection. Sinus infection may be the result of a cold that has become infected or may be caused by another underlying medical condition. Some common symptoms to look for to know if you have a sinus infection are:

Stuffy nose and face

One of the first signs of sinus infection is tenderness of your face. You’ll feel most of the pain under your eyes or at the bridge of your nose. This happens because your sinus cavities are full of mucus that isn’t draining properly. You may also experience nasal stuffiness or congestion. Pain in the teeth and frontal headaches are also common symptoms.

Postnasal drip

A post nasal drip is a common symptom of sinus infection. It can lead to sore throat because your excess mucus is full in your sinus cavity and draining down your throat. This irritates the back of your throat, causing it to feel sore and painful.


A persistent cough can be a sign of sinus infection. Your cough may be wet and feel mucusy. This is your body’s way of trying to clear your throat from mucus drainage.

Low-grade fever

A low-grade fever is another common symptom of sinus infection. It happens because your body is fighting an infection in your sinuses. If your fever lasts longer than four days and becomes very high, seek immediate medical attention.

Types of sinus infection

A sinus infection can appear in four different ways. Each way is based on the timeframe of the infection and how persistent it is. The four types of sinus infection are:

  • Acute sinusitis comes on suddenly and lasts less than four weeks.
  • Subacute sinusitis comes on like acute sinusitis but resolves within 12 weeks.
  • Chronic sinusitis happens when your symptoms persist longer than 12 weeks.
  • Recurrent acute sinusitis is when you have four or more acute sinus infections lasting seven days each, in a one-year span.

If your sinus infection lasts for long periods of time without any relief, even with the use of over-the-counter medicine, you should schedule an appointment with your doctor.

Causes of sinus infection

There may be several causes of sinus infection. Typically a sinus infection starts from a cold, and develops because the mucus in your sinus does not drain properly and causes an infection in your sinus cavity. Most sinus infections are viral but some are bacterial.

Allergies can also cause a sinus infection. More severe causes included a deviated septum, nasal bone spur, or polyps in your nose. If you have recurrent acute sinusitis, your doctor may run additional tests to rule out a different medical condition causing your sinus infections.

When to see the doctor for sinus infection

Symptoms that last more than 10 days without improvement and are worsening after you started to improve is cause for concern. If you have symptoms like severe headache or facial pain and a fever that lasts longer than three to four days, you should seek immediate medical care. Your doctor will be able to help diagnose the underlying cause of your symptoms and will provide an active plan of treatment.

While sinus infections are common, they can also be life-threatening. If a sinus infection becomes severe and goes untreated, it can spread to the brain.


Common Allergies: Symptoms and Signs See Slideshow

Diagnosing sinus infection

Recurrent sinus infection or worsening symptoms are cause for concern and you should schedule an appointment with your doctor. They will be able to diagnose your sinus infection and rule out if there are underlying medical conditions causing the infection.

Your doctor or allergist will give you a physical examination. They will look for markers of sinus infection, like swelling and tenderness in the face and discolored mucus.

To look for sinus infection they may use a fiberoptic scope to look in your nose for polyps or signs of inflammation. Sinus infections that do not go away can be diagnosed through allergy testing, blood tests, nasal culture, and tests for cystic fibrosis.

Treatments for sinus infection

Your treatment will depend on the severity of your sinus infection and how long it has lasted. Typically you can treat sinus infections at home using nasal decongestants or cough and cold medication.

Your doctor may prescribe an allergy medicine, such as antihistamines, to manage certain conditions. Symptoms that are severe may call for antibiotics if bacteria is causing the infection. If you are prescribed antibiotics, it is important to take the entire recommended dosage until the end of your treatment, even if you begin feeling better.

If maximum medication has not treated your sinus infection or your doctor suspects serious complications, they may recommend surgery to open up the sinus. However, that is usually a last resort and advancements in technology have allowed for less open sinus surgery.

American Academy of Allergy, Asthma, and Immunology: "Cold, Allergies and Sinusitis -- How to Tell The Difference."

American College of Allergy, Asthma and Immunology: "Sinus Infection."

British Medical Journal (BMJ): Sinusitis and its management."

Centers for Disease Control and Prevention: "Sinus Infection (Sinusitis)."

Family Doctor org: "Sinusitis."

Mount Sinai: "Sinusitis."

StatPearls: "Sinusitis."