The act of breathing is a rhythmic, seemingly effortless process that we often take for granted. With each breath, our lungs inflate, drawing in life-giving oxygen. But what happens when one of these vital organs suddenly collapses? This condition, known medically as pneumothorax, can cause abrupt, sharp chest pain and frightening shortness of breath. It occurs when air leaks into space between the lung and the chest wall, causing the lung to deflate like a punctured balloon. While a small collapsed lung may sometimes heal on its own, a larger one can be a serious medical emergency requiring immediate intervention. Understanding the causes, symptoms, and treatments for a collapsed lung is crucial for recognizing this dangerous condition and seeking timely care.

A collapsed lung, medically known as pneumothorax, occurs when air leaks into the space between the lung and the chest wall (the pleural space). To understand this, it is essential to first understand the basic anatomy of the chest cavity. Each lung is enclosed within a two-layered membrane called the pleura.

• The visceral pleura is the inner layer covering the lung surface.
• The parietal pleura is the outer layer that lines the inside of the chest wall.

Between these two layers is a very thin, fluid-filled area known as the pleural space. In a healthy person, this space contains a slight vacuum, or negative pressure. This negative pressure acts like a suction cup, holding the surface of the lung firmly against the chest wall and allowing it to expand and fill with air as you breathe in.

A pneumothorax happens when a hole develops in either the lung or the chest wall, allowing air to leak into this sealed pleural space. This breach destroys the negative pressure, breaking the suction that holds the lung open. Without this suction, the natural elasticity of the lung tissue causes it to pull inward and collapse, either partially or completely.

Healthcare providers classify a collapsed lung into several types based on its cause:

• Spontaneous Pneumothorax: This type occurs suddenly without any preceding injury. It is further divided into:
  • Primary Spontaneous Pneumothorax (PSP): Occurs in people with no known underlying lung disease.
  • Secondary Spontaneous Pneumothorax (SSP): Occurs as a complication of a pre-existing lung condition.
• Traumatic Pneumothorax: This is caused by a direct chest injury.
• Tension Pneumothorax: A medical emergency where trapped air builds up pressure, compressing the heart and lungs can lead to shock and death if untreated quickly.

A collapsed lung happens when air enters the pleural space. The underlying causes are the events that create the hole, allowing the air to leak in.

Causes of Spontaneous Pneumothorax

• Rupture of Blebs or Bullae: This is the most common cause of primary spontaneous pneumothorax. Blebs are small, weak, blister-like air sacs that can form on the surface of the lungs. For reasons that are not fully understood, these blebs can rupture, allowing air to leak from the lung into the pleural space.
• Underlying Lung Disease: In secondary spontaneous pneumothorax, a variety of lung diseases can weaken the lung tissue and lead to a rupture. The most common cause is Chronic Obstructive Pulmonary Disease (COPD). Other diseases include:
  • Cystic fibrosis
  • Asthma
  • Tuberculosis
  • Pneumonia
  • Lung cancer

Causes of Traumatic Pneumothorax

Any injury to the chest can potentially cause a lung to collapse.

• Blunt Trauma: A powerful blow to the chest, such as from a car accident, a hard fall, or a sports injury, can fracture ribs. The sharp, broken edge of a rib can then puncture the lung.
• Penetrating Trauma: Any injury that pierces the chest wall, such as a stab wound or a gunshot wound, can directly introduce air into the pleural space and puncture the lung.
• Iatrogenic Pneumothorax: This is a pneumothorax caused by a medical procedure. While doctors take great care to avoid this complication, it can sometimes occur during procedures like the insertion of a central venous line, a lung biopsy, or mechanical ventilation.

The risk factors for developing a pneumothorax are directly linked to the different types of pneumothorax and their underlying causes.

Risk Factors for Primary Spontaneous Pneumothorax (PSP): This type most commonly affects a very specific demographic. Key risk factors include:

• Being Male: PSP is significantly more common in men than women.
• Body Type: It is most commonly seen in tall, thin individuals.
• Age: It typically occurs in people between the ages of 20 and 40.
• Smoking: Smoking cigarettes (including cannabis) dramatically increases the risk of bleb formation and rupture.
• Genetics: A family history of spontaneous pneumothorax can increase a person’s risk.

Risk Factors for Secondary Spontaneous Pneumothorax (SSP):

• Having a pre-existing lung disease is the primary risk factor, with COPD being the most common.
• Older age (typically over 60), as this is when lung diseases like COPD are more prevalent.

Risk Factors for Traumatic Pneumothorax:

• Participating in high-impact or contact sports.
• Having a job or engaging in activities with a high risk of chest injury.

Symptoms depend on the extent of lung collapse and how quickly it develops.

The two classic, hallmark symptoms are:

• Sudden, sharp chest pain on one side of the chest. The pain is often described as stabbing and is typically made worse by taking a deep breath or coughing.
• Shortness of breath (dyspnea). This can range from mild difficulty breathing to severe respiratory distress.

Other common signs may include:

• Rapid heart rate (tachycardia)
• A dry, hacking cough
• A feeling of tightness in the chest
• Fatigue

Signs of a Tension Pneumothorax: A tension pneumothorax is a medical emergency that requires immediate intervention. Its signs are more severe and progress rapidly:

• Extreme and rapidly worsening shortness of breath and chest pain
• Very low blood pressure (hypotension) and signs of shock (such as a rapid, weak pulse and cool, clammy skin)
• Cyanosis (a bluish discoloration of the skin, lips, and nailbeds) due to lack of oxygen
• Distended neck veins

If you suspect you or someone else is experiencing these severe symptoms, call for emergency medical help immediately. It’s important to act quickly and seek emergency care.

Diagnosis

Diagnosis typically involves a clinical exam and imaging.

• Physical Examination: When a doctor listens to the chest with a stethoscope, they will hear decreased or absent breath sounds on the side of the collapsed lung. They may also tap on the chest (a technique called percussion) and hear a hollow, drum-like sound over the trapped air.
• Chest X-ray: This is the primary diagnostic tool for a collapsed lung. A standard chest X-ray can clearly show the air that has collected in the pleural space. The image will reveal the visible edge of the collapsed lung, which has pulled away from the chest wall. The X-ray also allows the doctor to estimate the size of the pneumothorax.
• Computed Tomography (CT) Scan: A CT scan, which provides a more detailed image, is not usually needed for the initial diagnosis but may be used later to look for the underlying cause, such as the presence of blebs or other lung abnormalities that might require surgical treatment.
• Arterial Blood Gas (ABG): This blood test measures the levels of oxygen and carbon dioxide in the arterial blood and can help assess how severely the collapsed lung is affecting the body’s ability to oxygenate.

Clinically, a chest X-ray is the fastest way to confirm pneumothorax.

Treatment

The specific treatment depends on the size of the pneumothorax, the severity of the symptoms, and the underlying cause.

1. Observation: For a very small primary spontaneous pneumothorax where the patient has minimal symptoms, the doctor may recommend observation alone. The body is capable of reabsorbing the small amount of leaked air from the pleural space over a period of days to weeks. This approach involves rest and follow-up chest X-rays to ensure the lung is re-expanding properly.

2. Needle Aspiration: For a larger pneumothorax, a simple procedure called needle aspiration may be performed. A doctor inserts a thin needle attached to a syringe through the chest wall into the pleural space and manually draws out the trapped air.

3. Chest Tube Insertion (Tube Thoracostomy): This is the standard treatment for a symptomatic collapsed lung.

• A flexible plastic tube is inserted through an incision in the chest wall into the pleural space.
• This chest tube is then connected to a device with a one-way valve system. This system allows the trapped air to bubble out of the chest but prevents it from being drawn back in when the person inhales.
• This process removes the air from the pleural space, allowing the negative pressure to be re-established so the lung can re-inflate. The tube is usually left in place for several days until the lung has fully healed and the air leak has sealed.

4. Procedures to Prevent Recurrence The recurrence rate after a first spontaneous pneumothorax is high, sometimes approaching 50%. If a person has a recurrent collapsed lung, a doctor will likely recommend a procedure to prevent it from happening again.

• Pleurodesis: In this procedure, an irritating substance (like a talc slurry or a doxycycline solution) is introduced into the pleural space through the chest tube. This causes the two layers of the pleura to become inflamed and stick together, effectively obliterating the pleural space so air can no longer accumulate there.
• Surgery: A minimally invasive surgical procedure called Video-Assisted Thoracoscopic Surgery (VATS) may be recommended. A surgeon makes small incisions and uses a tiny camera and long instruments to find and remove the ruptured air blebs. At the same time, they will usually perform a pleurodesis to prevent recurrence.

A collapsed lung, or pneumothorax, is a serious medical condition that occurs when air leaks into the space between the lung and chest wall, causing the lung to deflate. While it can result from a traumatic chest injury, it can also happen spontaneously, most commonly in tall, thin young men or in older individuals with underlying lung disease. The sudden onset of sharp, one-sided chest pain and shortness of breath should never be ignored. With modern diagnostic imaging and effective treatments ranging from simple observation to chest tube placement and surgery, most people recover fully.

• American Lung Association. (2024). Pneumothorax. Retrieved from https://www.lung.org/lung-health-diseases/lung-disease-lookup/pneumothorax
• Mayo Clinic. (2022). Pneumothorax. Retrieved from https://www.mayoclinic.org/diseases-conditions/pneumothorax/symptoms-causes/syc-20350367
• National Heart, Lung, and Blood Institute (NHLBI). (2022). What is a collapsed lung? Retrieved from https://www.nhlbi.nih.gov/health/collapsed-lung