Atelectasis

3 things to know first

1. It is not a tumor. Atelectasis means part of the lung is collapsed or under-inflated.
2. It is very common after surgery or shallow breathing. Small bands of atelectasis are often seen on chest scans.
3. Most cases are mild and reversible. Deep breathing, movement, or treatment of mucus can help the lung re-expand.

What it is

Atelectasis refers to a partial or complete collapse of a portion of the lung. When this happens, the tiny air sacs (alveoli) lose air and become smaller and denser than normal. It can involve a small subsegment of one lobe or, less commonly, a larger area.

There are several types. Obstructive atelectasis occurs when a mucus plug or foreign body blocks an airway. Compressive atelectasis occurs when something outside the lung presses on it, such as fluid or a tumor. Passive or platelike atelectasis appears as thin bands, often at the bottom of the lungs, and is very common.

Why it appears on your report

Radiologists use the term atelectasis when they see a band, patch, or volume loss in the lung on X-ray or CT. It usually appears as a linear or triangular area of increased density, often near the lung bases. The finding is common after surgery, with shallow breathing, or when a person has been lying flat.

How serious is it

Atelectasis is usually not serious when it is small. Severity depends on:

• Extent: Small platelike bands are very common and usually harmless. Larger areas can cause low oxygen levels.
• Cause: A mucus plug is usually treatable. Compression from fluid or a mass needs the underlying cause addressed.
• Symptoms: Many people have no symptoms. Others may feel short of breath or have a mild cough.

In children or after surgery, atelectasis can contribute to breathing problems, but it usually improves with care.

When to seek care urgently

Seek urgent care if atelectasis is accompanied by:

• Severe shortness of breath or difficulty breathing
• Chest pain or a high fever
• Coughing up blood
• Blue-tinged lips or fingertips

What usually happens next

1. Assess symptoms. Your doctor will check whether you have cough, fever, or breathing difficulty.
2. Address the cause. If mucus is the problem, treatments may include hydration, breathing exercises, or airway clearance.
3. Encourage lung expansion. Incentive spirometry, deep breathing, walking, and changing positions help reopen the lung.
4. Follow-up imaging if needed. If the area does not clear or looks unusual, a repeat scan may be ordered.

A simple analogy

Think of the lungs as a bunch of tiny balloons. If some balloons stop getting air, they shrink and bunch together. Once you take a deep breath or clear the straw they are attached to, they can inflate again.

Further reading

• MedlinePlus — Atelectasis
• Radiopaedia — Atelectasis