Symptoms and causes

What is it?

Sinus inflammation, often called sinusitis, is an acute infection of the mucous in the nasal sinuses. The inflammation is usually caused by a virus and is similar to a common cold. There are two types of sinusitis: acute sinusitus and chronic sinusitis.

Sinuses are air-filled cavities in the cranium, next to and above the nose, the eyes, the upper jaw and the forehead. The swelling of the mucousal membranes makes it difficult to empty the mucous, (secretions) and it collects in the sinuses. In some cases, there can be an additional bacterial infection.

In young children, these sinuses are not yet fully developed and so they rarely have this condition.


Acute sinusitis

  • nasal congestion
  • yellow/green mucous in front of and behind the nose, which can drip down into the throat (post-nasal drip), sometimes resulting in a cough
  • reduced sense of smell (and possibly of taste)
  • feeling of pressure in the face, along the upper teeth

These are the most common symptoms of acute sinusitis and they usually improve after a few weeks.

Chronic sinusitis

  • a sinus infection that lasts for twelve weeks or longer

In addition, the other symptoms present are similar to the symptoms of an acute infection, only that they last a lot longer and keep coming back.

Diagnosis and treatment


Acute sinusitis

Your physician can make the diagnosis based on your symptoms and on a clinical exam of the nose using an endoscopy. Medical imaging is not indicated for an acute infection, unless complications arise. In rare cases, the infection can spread to the nearby eye socket or to the brain.

Chronic sinusitis

The physician makes the diagnosis based on patient history (your medical history, current health, etc.), a clinical exam with the nasal endoscopy and a CT scan of the sinuses. In healthy sinuses, there is air (which appears black on the scan) in the sinuses. If the sinuses are infected, this area appears gray on the scan.


Acute sinusitis

In most cases, the sinusitis resolves on its own, just like a common cold. Pain medication, nasal sprays, and nasal rinses can alleviate symptoms. If there is a bacterial infection, treatment with antibiotics will be started.

Chronic sinusitis

For mild symptoms, a corticosteroid nasal spray with nasal rinses can be sufficient. For serious symptoms, a long course of antibiotics may be considered, perhaps along with a short course of cortisone pills. In addition, a procedure may be performed in order to widen the sinus drainage passages. This is called a functional endoscopic sinus surgery (FESS).

Treatment centres and specialisations

Ear, nose, and throat diseases

Latest publication date: 11/08/2021
Supervising author: Dr Vermeiren Judith