Which Type Of Atelectasis Is The Most Common?

Which Type Of Atelectasis Is The Most Common?

There are about three major types of atelectasis namely obstructive, non-obstructive and adhesive. Among the three, the most common is the obstructive atelectasis whereas the former is the least common. The different types of atelectasis have their own unique traits including different etiology and radiographic pattern. A collapsed lung is the resulting effect of atelectasis and the entire lung or part of it may be implicated. Consequently, oxygen levels in the body decline as an obstruction in the airways put a strain on one’s ability to breathe properly. The manner in which obstructive atelectasis manifests is solely dependent on the underlying cause.

Obstructive Atelectasis

There are a few factors which can cause obstructive atelectasis, which tends to result in reabsorption of gas from the alveoli. Majorly, the cause is usually obstruction of the bronchial airways by either inhaled foreign objects, tumor, or mucus plugging. Foreign objects can easily get in your nasal cavity and find their way into the lung cavity where the bronchi are located. Regardless of whether the objects are small or large, they can cause blockage thus interfering with respiration. In turn, the lungs are denied enough oxygen to function properly and they can collapse easily.

The respiratory tract is covered with a thin lining of mucus, enough to enhance normal functionality. However, when one has pulmonary infections or diseases, say pneumonia or tuberculosis, it can lead to thick mucus which can easily obstruct the air passages. As for tumors, they apply pressure on the lungs and thus pressing on the alveoli where gaseous exchange takes place. In turn, the function of the air sacs (alveoli) is compromised and they collapse.

Signs and Symptoms

In cases of acute atelectasis where there is an obstruction, a patient may show the following signs and symptoms:

  • Dyspneashortness of breath and difficulty breathing
  • Diminished breath sounds over the affected lung
  • Cyanosis – bluish (cyan) discoloration of skin on the side of the affected lung
  • Increase temperature (fever)
  • Drop in blood pressure
  • Low oxygen saturation


Obstructive, also known as absorption or resorptive atelectasis, can be diagnosed through a physical or an x-ray examination. In an x-ray, the results show a shadow in the area of the collapsed lung. If the entire lung has collapsed, the x-ray indicates a slight deviation of the trachea, heart, and mediastinum towards the side of the collapsed lung. Physical examination involves investigating for absent or quick breath sounds that are strained. In addition to that, a CT scan can be conducted to further clarify the condition. The imaging gives a clearer view of the collapsed and also pinpoints the obstruction and its location. Also, a bronchoscopy can be done where a fiber-optic scope is trailed down to the respiratory tract via the mouth. It helps in identifying the cause of obstruction and can also be used as a treatment method. Oxygen levels can be tested in your blood either using an oximeter or doing a blood gas test.


Treatment of atelectasis depends on the underlying cause and the extremity of the condition. Resorptive atelectasis can be treated using nonsurgical methods or surgical procedures. Chest physiotherapy involves deep breathing, coughing as well as percussion and postural drainage. On the other hand, medication therapy involves prescription of drugs to improve the condition and treat the underlying cause. Antibiotics are given to treat infections whereas inhaled bronchodilators help open up obstructed bronchial tubes and acetylcysteine thins mucus causing airway obstruction.

Surgical procedures can be performed to remove airway obstruction via a bronchoscopy or to entirely remove the affected part (lobe) of the lung. Surgery may also be done to remove a tumor if that is what is causing the obstruction. Alternatively, chemotherapy, radiation or laser therapy can be applied to shrink the tumor.


Obstructive atelectasis will occur when there is an obstruction interfering with the communication between the alveoli and trachea. This can either be due to mucus plugging, foreign body or tumor. The extent of collateral ventilation is crucial in this most common type of atelectasis as it affects the rate at which the condition develops. Obstructive atelectasis can include labor atelectasis (obstruction of the labor bronchus) or segmental atelectasis (obstruction of the segmental bronchus). Any type of atelectasis, including obstructive atelectasis, should not be ignored as it can lead to fatal health complications.

Also Read: