What is Sinus infection (Sinusitis)? Symptoms, Causes, Treatment


The paranasal sinuses are four pairs of cavities located within the facial massif, the anterior part of the skull. They are in communication with the nasal cavities through small ducts that allow the passage of mucus and each takes its name from the bone in which it is located. Sinus inflammation is a condition that is called sinusitis. Thus we will have the sinuses

  • Maxillary,
  • Frontal,
  • Ethmoidal
  • And sphenoid.

Sinus inflammation is a condition that is called sinusitis.
Sinusitis occurs with many symptoms that generally include

  • Ache,
  • Fever
  • Sense of congestion in the face.

In most cases the cause is infectious in nature and, depending on the duration, can be classified as

  • Acute,
  • Sub-acute
  • Or chronic.

Below we will try to explain all the features of this pathology. However, reading this article does not represent an alternative to the opinion of the attending physician.

What are the Main Causes of Sinus infection (sinusitis)

Mostly in all cases, it is caused by an infection, which can however have different origins:

Viral infection: It is the most common and is caused by the same viruses that normally infect the airways, such as rhinoviruses, coronaviruses, or influenza viruses. The viral form is usually less severe than the bacterial form and can occur after a cold or bronchitis.

Bacterial Infection: Some of the most frequently involved bacteria are Streptococcus pneumonia, Haemophilus influenzae, Staphylococcus aureus, and Moraxella catarrhalis. Bacterial sinusitis usually develops from an already existing focus of infection, often located in the upper digestive tract (for example in the pharynx or in the dental arches ).

There are also non-infectious forms caused by the obstruction of the drainage ostium or the passage that connects the sinuses with the nasal cavities. In the event that this passage is blocked, the mucus produced by the paranasal sinuses can no longer be drained and stagnates inside them, thus favoring the onset of inflammation.
The obstruction may be due to several factors, like

  • Septal deviation,
  • Nasal polyposis
  • Or the presence of a foreign body inside the cavity (more common in children).

However, it is important to specify that these causes are not to be considered independent; the stagnation of mucus, for example, favors the growth of microorganisms inside the paranasal sinuses, thus favoring an overlap between infectious and non-infectious forms.

Risk factors of Sinusitis

A risk factor is a condition that, while unable to cause disease, makes us more vulnerable to it directly. Below we list the main risk factors for sinusitis:

  • Cold,
  • Cigarette smoke,
  • Dry air,
  • Allergies,
  • Excessive utilization of nasal decongestants.


Depending on the duration of the symptoms we distinguish sinusitis:

  • Acute (less than 4 weeks),
  • Sub-acute (between 4 and 12 weeks),
  • Chronic (more than 12 weeks).

Instead, we speak of recurrent sinusitis if the same patient has more than three episodes in the course of a year.
Chronic, recurrent, or unresponsive sinusitis may lead to suspicion of the presence of predisposing factor or an anatomical malformation and therefore deserve to be adequately investigated.

Transmission and contagiousness

As a rule, the individual suffering from sinusitis of infectious origin is contagious for the duration of the symptoms, but it is important to make some distinctions:

  • Most sinus infections are caused by viruses; the infection is therefore contagious, but the person to whom it’s transferred could develop a different type of infection, like cold or pharyngitis. The main mode of transmission is liquid particles suspended in the air we breathe. However, it is possible that the infection occurs due to contact with dirty surfaces (handshakes, handles, or others), above all due to inadequate hygienic conditions.
  • When the infection lasts longer than 10-14 days it is more likely that it is bacterial sinusitis, which is typically not contagious.

Man lying on the bed, touching sinus region due to sinus pain.
The symptoms of sinusitis are more intense in the acute forms, while they become more nuanced or even absent in the chronic forms. Presentation includes:

  • Pain: The most common symptom is pain in the face, which is aggravated by sudden movements of the nose or by putting pressure on the affected area.

The pain is localized on the forehead, at the root of the nose, around the eyes, or in the jaw. Depending on which sinuses are affected by the disease. It is curious to note how the site of inflammation differs according to age: in children, it is more common in the upper part of the nose (ethmoid sinus), while in adults the maxilla (maxillary sinus) is more often involved.

  • Nasal congestion: Caused by the accumulation of mucus, congestion can be accompanied by rhinorrhea (expulsion of mucus from the nose) and rhinolalia (nasal voice). In severe cases, it can become responsible for breathing difficulties.
  • Headache: The headache caused by sinusitis can be very intense and tends to get worse in the early morning hours.
  • Fever: Although it is an infectious picture, fever is not always present (it is detected in about half of cases).
  • Hyposmia: Hyposmia is the reduction of the sense of smell and is caused by inflammation of the nasal mucosa.


Diagnosis is often relatively simple and can be made on the basis of the patient’s symptoms and physical examination.
There is also a series of instrumental tests which can be used to clarify and identify the causes of the disease (in particular when there is suspicion of an anatomical defect such as deviation of the nasal septum) or to confirm the diagnosis.

  • Rhinoscopy: It is an endoscopic technique that consists of the introduction of a probe equipped with a camera. It allows you to explore the nasal cavities and paranasal sinuses, thus verifying the state of inflammation and the possible presence of malformations, polyps, or foreign bodies.
  • Radiography: Radiography uses ionizing radiation (X-rays) to obtain an image of the cranial bones and their cavities. It may show some signs of ongoing sinusitis, however, it is an insensitive technique and has the disadvantage of using radiation (which, although administered in minimal quantities, is harmful to the body).
  • Computed Axial Tomography or CT: Computed Axial Tomography (abbreviated to CT or CT) is a method that allows you to obtain very precise images of both the bones and soft tissues of the patient and is the technique of choice for observing the morphology and contents of the paranasal sinuses. It is mainly used for chronic sinusitis. The disadvantages of this method are the high cost and the use of ionizing radiation (to a greater extent than radiography).

Prognosis and complications

Prognosis largely depends on the form of sinusitis.

  • In the case of viral sinusitis, it is excellent and healing usually takes place within a week, even without treatment.
  • Bacterial sinusitis, on the other hand, has a longer duration on average, even if spontaneous healing is possible. It must be subjected to antibiotic treatment in order to avoid the risk of chronicization and the onset of complications.
  • In the case of anatomical anomalies, in the presence of nasal polyps or foreign bodies, and in the case of recurrent sinusitis, surgical treatment may also be indicated.

The possible complications of sinusitis are:

  • Meningitis: Inadequately treated infection can reach the meninges, the sheaths that cover and protect the brain. In this case, the clinical picture is destined to worsen. In addition to fever and headache, vomiting, neck rigidity, altered consciousness and convulsions may appear. It can be fatal, especially in very young or old people.
  • Brain abscess: It represents a serious picture. The infection affects the brain causing a zone of necrosis (cell death) in it. This is a real medical emergency that can cause permanent brain damage or patient death, so it needs to be treated immediately.
  • Orbital cellulitis: It is a typical complication of the child and consists of the propagation of the infection to the periocular tissues (remember that at a young age sinusitis tends to localize in the ethmoid sinus, which is very close to the eye). It manifests with pain, exophthalmos (ie protrusion of the eyeball), eyelid erythema, and difficulty in moving the eye.

Treatment and remedies for Sinus infection or Sinusitis

Up to 70% of forms of acute sinusitis heal without the need for drugs; when the reason is bacteria. Treatment with an antibiotic may speed up the course and reduce the severity of symptoms.
sinusitis Treatment includes:

  • Nasal washes: They are carried out with hydro-saline solutions that thin the excess mucus and thus help to clean up the nasal cavities. They are usually associated with drug therapy.
  • Medicines
  • Surgery: Surgical therapy reserves for chronic, relapsing, or unresponsive forms of drug therapy. The operation is normally performed endoscopically, using a thin instrument that is inserted through the nose and has the purpose of widening the drainage channels of the paranasal sinuses.

Sinusitis Medications

  • Nasal decongestants: These are medicines that are usually given in the form of a nasal spray. They act as vasoconstrictors, that is, they decrease the amount of blood directed to the nasal mucosa which is reduced in thickness, thus favoring the escape of mucus. They are very effective drugs. Their use should not be continued for a long time. Otherwise, there will be a loss of effectiveness or even damage to the nasal mucosa (it is advisable not to take them for more than five days).
  • Anti-inflammatory: They reduce mucosal inflammation and pain, thereby relieving the patient’s symptoms. They can be systemic (i.e. act throughout the body) or topical (if administered nasally and act only there). Mostly non-steroidal anti-inflammatory drugs use (also known by the acronym NSAID), while in more serious cases the doctor may opt for a cortisone-based treatment.
  • Antibiotics: Bacterial sinusitis should be treated by introducing antibiotic therapy, usually lasting one or two weeks. A drug widely used in these cases is the combination of amoxicillin and clavulanic acid, two active ingredients that act synergistically and are effective against a broad spectrum of pathogenic bacteria; the doctor (treating, otolaryngologist, internist, … ).

However, will be able to choose the most appropriate therapy by knowing the patient’s history and evaluating the epidemiological characteristics of the geographical area of ​​his competence. Once antibiotic therapy has begun; it is very important to take it regularly until the end and not to suspend it when symptoms are resolved, in order to avoid the onset of drug-resistant bacterial strains.

  • Antihistamines: They can be useful in resolving the symptoms of sinusitis when allergic phenomena cause it.

Natural remedies

  • To find relief it is recommended
  • apply warm-moist compresses to the face several times a day
  • drink abundantly to promote mucus thinning
  • fumigate 3-4 times a day
  • nasal washes with saline solution
  • humidify the environment

During the acute phases, certain behaviors can cause pain to worsen. Such as air flights, temperature changes, and body positions that involve a position of the head tilted forward.


The prevention of sinusitis essentially involves the elimination of risk factors, including:

  1. avoid exposure to extremely cold conditions,
  2. humidify the rooms where you live,
  3. stop smoking.

As for infectious sinusitis, it is important to protect yourself from contagion by adopting adequate hygiene rules (especially frequent handwashing) when you come into contact with sick people.