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Educational use only: Symptom.Today is an educational tool and does not provide medical advice, diagnosis, or treatment. Results are not a substitute for professional medical care. If symptoms are severe, worsening, or concerning, seek medical attention immediately. In an emergency, call your local emergency number.
RespiratoryModerate

Atelectasis

Atelectasis is the partial or complete collapse of a lung or a section (lobe) of a lung. It occurs when the tiny air sacs (alveoli) within the lung become deflated or filled with alveolar fluid.

Severity
Moderate
System
Whole body
Progression
Gradual
Treatable
Yes — usually with self-care or routine treatment
Common age
All ages
Duration
Acute (days–weeks)
Contagious
No
Emergency risk
High
Whole body
Affected area: Whole body

Overview

Atelectasis is the partial or complete collapse of a lung or a section (lobe) of a lung. It occurs when the tiny air sacs (alveoli) within the lung become deflated or filled with alveolar fluid.

Understand this condition

The lungs are made of tiny sacs called alveoli that should stay inflated like balloons. In atelectasis, these sacs lose air and flatten, preventing oxygen from entering the bloodstream. This makes the affected part of the lung useless for breathing until it reflates.

Why it happens

It occurs when pressure outside the lung or a blockage inside the airway stops air flow. This usually starts with shallow breathing or a mucus plug that traps air in the sacs. Over time, the trapped air is absorbed by the body, causing the sacs to deflate.

Real-world scenarios

  • This often appears as shortness of breath after abdominal surgery.
  • People may notice a persistent cough after inhaling food or small objects.
  • This often appears as sharp chest pain during deep inhalations.
  • People may notice rapid, shallow breathing while recovering from an injury.

Common vs serious explanations

Common
  • Temporary shallow breathing after recent surgery
  • Mild mucus buildup from a common cold
  • Inactivity or prolonged bed rest after illness
Serious
  • Pneumothorax, where air leaks into the space around the lung.
  • Severe pneumonia causing significant lung inflammation.
  • A large tumor obstructing a primary bronchial tube.
  • Pulmonary embolism blocking blood flow to lung tissue.

Symptoms

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Primary symptoms

No symptoms mapped yet.

Causes

  • Blockage of the airway by mucus or a foreign object
  • Pressure from outside the lung (pleural effusion or tumor)
  • Shallow breathing due to pain or anesthesia
  • Scarring of lung tissue

Risk factors

  • Recent abdominal or chest surgery
  • Prolonged bed rest or immobility
  • Chronic lung diseases like COPD or asthma
  • Smoking
  • Obesity

How it progresses

3 stages
  1. Onset
    Symptoms appear, often triggered by a known cause.
    Often missed
  2. Active phase
    Symptoms peak; self-care or short treatment usually helps.
  3. Resolution
    Symptoms ease over days to weeks with proper care.

How it's diagnosed

  • Chest X-ray
  • Chest CT scan
  • Pulse oximetry to measure oxygen levels
  • Bronchoscopy

Treatment options

General educational information only — no dosage advice. Always follow guidance from a qualified clinician.

Medical
  • Chest physiotherapy (percussion)
  • Inhaled medications to open airways
  • Suctioning of mucus or blockages
  • Continuous positive airway pressure (CPAP)
Home care
  • Deep breathing exercises (incentive spirometry)
  • Frequent position changes
  • Increasing fluid intake to thin mucus
  • Effective coughing techniques (huff coughing)

Complications

  • Reduced quality of life
  • Worsening symptoms over time
  • Recurrence of atelectasis

Prevention

  • Maintain a healthy lifestyle
  • See a clinician for routine check-ups

When to seek help

Urgent — same-day care
  • Symptoms persist beyond a few days
  • Symptoms interfere with daily activities
  • New or worsening symptoms appear
  • Concerning changes related to atelectasis
🚨 Emergency — call now
  • Sudden difficulty breathing
  • Bluish tint to lips or skin (cyanosis)
  • Rapid heart rate
  • Sharp chest pain

In any emergency, call your local emergency number or go to the nearest emergency department.

Real-world questions

  • Can Atelectasis cause headaches?
  • Is Atelectasis reversible?
  • How quickly does Atelectasis progress?
  • Is Atelectasis hereditary?
  • Can Atelectasis be prevented?

Frequently asked questions

What causes Atelectasis?

Possible causes of Atelectasis include Blockage of the airway by mucus or a foreign object, Pressure from outside the lung (pleural effusion or tumor), Shallow breathing due to pain or anesthesia, Scarring of lung tissue.

Is Atelectasis dangerous?

Atelectasis is generally moderate, but severity can vary. Seek care if symptoms are severe or persistent.

How long does Atelectasis last?

Duration varies between individuals. Many cases improve with appropriate care, while others may persist longer and require ongoing management.

Can Atelectasis go away on its own?

Some milder cases may improve with rest and self-care. If symptoms persist or worsen, consult a healthcare professional.

When should I see a doctor about Atelectasis?

Consider seeing a clinician if symptoms are severe, persistent, worsening, or if you have any concerns related to general.

Sources

Information based on general medical references such as:

CDCNHSWHOMedlinePlus

Last reviewed: May 2026

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Educational use only: Symptom.Today is an educational tool and does not provide medical advice, diagnosis, or treatment. Results are not a substitute for professional medical care. If symptoms are severe, worsening, or concerning, seek medical attention immediately. In an emergency, call your local emergency number.