Pneumothorax: Symptoms, Causes & Treatment of Collapsed Lung

What Is Pneumothorax (Collapsed Lung)?

Pneumothorax is a condition where air accumulates in the pleural space - the area between the lung and the chest wall. This air pressure causes the lung to collapse partially or completely, leading to sudden chest pain and difficulty breathing. The condition can be spontaneous or result from injury or underlying lung disease.

The lungs are surrounded by a thin, double-layered membrane called the pleura. The space between these layers (pleural space) normally contains only a small amount of lubricating fluid that allows the lungs to expand and contract smoothly during breathing. When air enters this space, it disrupts the normal negative pressure that keeps the lungs inflated, causing them to collapse.

The severity of a pneumothorax depends on how much air has accumulated and whether it continues to leak. A small pneumothorax may cause only mild symptoms and can sometimes resolve on its own as the body gradually absorbs the trapped air. However, a large or tension pneumothorax is a medical emergency that can be life-threatening if not treated promptly.

Pneumothorax affects approximately 7-18 per 100,000 men and 1-6 per 100,000 women each year. The condition is notably more common in tall, thin individuals and smokers. Understanding the causes, symptoms, and treatment options is essential for proper management and prevention of recurrence.

Types of Pneumothorax

There are several types of pneumothorax, each with different causes and characteristics. Understanding these distinctions helps guide appropriate treatment decisions.

Primary spontaneous pneumothorax (PSP) occurs in people without apparent underlying lung disease. It typically affects tall, thin young men between ages 15-34 and is strongly associated with smoking. Small air blisters (blebs) on the lung surface may rupture spontaneously, allowing air to escape into the pleural space.

Secondary spontaneous pneumothorax (SSP) occurs in people with underlying lung disease such as chronic obstructive pulmonary disease (COPD), asthma, cystic fibrosis, or lung infections. This type tends to be more serious because the underlying lung disease makes recovery more difficult.

Traumatic pneumothorax results from chest injury, such as from a car accident, fall, or penetrating wound. It can also occur as a complication of medical procedures like lung biopsy, central venous catheter placement, or mechanical ventilation.

Tension pneumothorax is the most dangerous type, where air continuously enters the pleural space but cannot escape, creating a one-way valve effect. This causes increasing pressure that shifts the heart and major blood vessels (mediastinal shift), potentially leading to cardiovascular collapse if not treated immediately.

What Are the Symptoms of Pneumothorax?

The main symptoms of pneumothorax include sudden, sharp chest pain on the affected side that worsens with breathing, shortness of breath (dyspnea), rapid breathing, and rapid heart rate. The severity of symptoms depends on the size of the pneumothorax and whether the patient has underlying lung disease.

Pneumothorax symptoms typically appear suddenly and can range from mild discomfort to severe respiratory distress. The most characteristic feature is the abrupt onset of symptoms, often occurring at rest or during normal activities rather than during exercise.

Chest pain is usually the first symptom patients notice. The pain is typically described as sharp, stabbing, or pleuritic (worsening with breathing) and is located on the same side as the collapsed lung. Many patients report that the initial pain is quite severe but then diminishes over the first 24 hours even though the pneumothorax remains.

Shortness of breath is the second most common symptom. The degree of breathlessness depends on the size of the pneumothorax and the patient's underlying lung function. A young, healthy person with a small pneumothorax may have minimal breathing difficulty, while someone with COPD and even a moderate pneumothorax may experience severe respiratory distress.

Common Symptoms

• Sudden, sharp chest pain on one side that may radiate to the shoulder or back
• Pleuritic chest pain that worsens with deep breathing, coughing, or laughing
• Shortness of breath (dyspnea) that may be mild to severe
• Rapid breathing (tachypnea) as the body tries to compensate
• Rapid heart rate (tachycardia)
• Dry, non-productive cough
• Feeling of tightness in the chest

Symptoms of Severe or Tension Pneumothorax

A tension pneumothorax is a life-threatening emergency where air continues to enter the pleural space but cannot escape, causing increasing pressure. This type requires immediate medical attention. Symptoms of tension pneumothorax include all of the above plus more severe signs of distress.

As pressure builds, the heart and major blood vessels are pushed to the opposite side of the chest (mediastinal shift), which can severely compromise blood circulation. This can lead to cardiovascular collapse and death if not treated within minutes.

Symptoms May Be Subtle

It is important to note that symptoms are not always dramatic. Some patients with small pneumothorax may have only mild chest discomfort or feel slightly short of breath. The absence of severe symptoms does not mean the condition is not serious - even small pneumothorax requires medical evaluation.

In some cases, particularly with secondary spontaneous pneumothorax in patients with underlying lung disease, symptoms may be attributed to the pre-existing condition rather than a new pneumothorax. This can delay diagnosis and treatment.

What Causes Pneumothorax?

Pneumothorax can be caused by chest trauma, underlying lung diseases (such as COPD, asthma, or cystic fibrosis), rupture of small air blisters (blebs) on the lung surface, or it can occur spontaneously without any apparent cause. Smoking increases the risk approximately 20-fold in men and is the most important modifiable risk factor.

Understanding the causes of pneumothorax helps identify risk factors and guide prevention strategies. The underlying mechanism in all types is the same - air enters the pleural space through a hole in the lung surface or chest wall - but the reasons for this occurring vary considerably.

Primary Spontaneous Pneumothorax

Primary spontaneous pneumothorax occurs in people without obvious lung disease. Despite the name "primary," most cases are actually caused by small air blisters called blebs or bullae on the lung surface that rupture. These blebs are not visible on standard chest X-rays but can be detected with CT scanning in up to 90% of patients.

The formation of these blebs is strongly linked to smoking. Cigarette smoke causes inflammation and degradation of lung tissue, particularly in the upper parts of the lungs where blebs most commonly form. The risk of primary spontaneous pneumothorax is approximately 20 times higher in male smokers compared to non-smokers.

Other factors associated with primary spontaneous pneumothorax include:

• Tall, thin body type (ectomorphic habitus): The reason for this association is not fully understood but may relate to the mechanical stress on the lung apex in tall individuals
• Male sex: Men are affected 3-6 times more often than women
• Age 15-34 years: This is the peak age group for primary spontaneous pneumothorax
• Family history: Genetic factors may predispose some individuals to bleb formation
• Changes in atmospheric pressure: May trigger rupture in susceptible individuals

Secondary Spontaneous Pneumothorax

Secondary spontaneous pneumothorax occurs as a complication of existing lung disease. The underlying condition damages the lung tissue, making it more susceptible to rupture. This type is generally more serious because the patient's respiratory reserve is already compromised by their underlying condition.

Common underlying conditions include:

• Chronic obstructive pulmonary disease (COPD): The most common cause of secondary spontaneous pneumothorax
• Asthma: Particularly severe or poorly controlled asthma
• Cystic fibrosis: Pneumothorax is a common complication
• Tuberculosis: Both active and previous infection
• Pneumonia: Especially necrotizing pneumonia
• Lung cancer: Can cause pneumothorax through various mechanisms
• Interstitial lung diseases: Such as pulmonary fibrosis or lymphangioleiomyomatosis (LAM)
• Marfan syndrome and Ehlers-Danlos syndrome: Connective tissue disorders affecting lung tissue

Traumatic Pneumothorax

Traumatic pneumothorax results from injury to the chest. The injury can be penetrating (such as a stab wound or gunshot) or blunt (such as from a car accident or fall). Medical procedures can also cause iatrogenic (procedure-related) pneumothorax.

Common causes of traumatic pneumothorax include:

• Rib fractures: Broken ribs can puncture the lung
• Penetrating chest wounds: Stab wounds, gunshot wounds
• Blunt chest trauma: Car accidents, falls, sports injuries
• Central venous catheter insertion: Particularly subclavian and internal jugular catheters
• Lung biopsy: Both percutaneous and transbronchial biopsy
• Mechanical ventilation: Especially with high pressures (barotrauma)
• Thoracentesis: Procedure to remove fluid from the pleural space

When Should You Seek Medical Care?

Seek immediate medical care if you experience sudden chest pain and difficulty breathing. Call emergency services if you have severe breathing difficulty, chest pain that is getting worse, bluish skin color, or feel faint. Even mild symptoms of chest pain and breathlessness warrant medical evaluation.

Pneumothorax always requires medical evaluation. While small cases may resolve with observation alone, only a healthcare provider can determine the size and severity of the pneumothorax and recommend appropriate treatment. Delaying care can allow a small pneumothorax to progress to a larger one.

The urgency of seeking care depends on the severity of symptoms. However, it is important to remember that the severity of symptoms does not always correlate with the size of the pneumothorax. Some patients with large pneumothorax may have relatively mild symptoms, while others with smaller pneumothorax may feel quite unwell.

Seek Emergency Care (Call Emergency Services) If:

• You have severe difficulty breathing or feel like you cannot get enough air
• Your skin or lips turn bluish (cyanosis)
• Your chest pain is severe and getting progressively worse
• You feel faint, dizzy, or confused
• You have a known lung condition and develop new chest symptoms
• You have had chest trauma

Seek Same-Day Medical Care If:

• You have sudden chest pain that worsens when you breathe deeply
• You feel more short of breath than usual
• You have mild chest discomfort with a dry cough
• You have had a previous pneumothorax and notice similar symptoms

How Is Pneumothorax Diagnosed?

Pneumothorax is diagnosed primarily through chest X-ray, which shows the collapsed lung and air in the pleural space. Physical examination may reveal decreased breath sounds on the affected side and hyperresonance to percussion. CT scan is used for small pneumothorax or to identify underlying lung disease.

Diagnosis of pneumothorax typically begins with a medical history and physical examination, followed by imaging studies. In emergency situations, particularly when tension pneumothorax is suspected, treatment may be initiated based on clinical findings before imaging can be obtained.

Physical Examination

During the physical examination, the doctor will listen to your chest with a stethoscope and may tap (percuss) on your chest. Key findings that suggest pneumothorax include:

• Decreased or absent breath sounds on the affected side
• Hyperresonance to percussion - the chest sounds more hollow when tapped
• Decreased chest wall movement on the affected side during breathing
• Tracheal deviation - in tension pneumothorax, the windpipe may be pushed toward the unaffected side
• Subcutaneous emphysema - crackling sensation under the skin from trapped air

Chest X-Ray

Chest X-ray is the primary diagnostic imaging test for pneumothorax. It can show the collapsed lung as well as the amount of air in the pleural space. The X-ray is typically taken with the patient standing and exhaling completely (expiratory film), which makes small pneumothorax easier to see.

On the X-ray, pneumothorax appears as a visible lung edge with no lung markings beyond it. The size of the pneumothorax can be estimated by measuring the distance between the lung edge and the chest wall.

CT Scan

Computed tomography (CT) scan is more sensitive than chest X-ray for detecting small pneumothorax. It is particularly useful in the following situations:

• When X-ray findings are uncertain
• To evaluate for underlying lung disease
• To look for blebs or bullae that might explain the cause
• When planning surgical treatment
• In trauma patients with multiple injuries

Other Tests

Additional tests may be performed depending on the clinical situation:

• Arterial blood gas analysis: Shows oxygen and carbon dioxide levels and can indicate how severely breathing is affected
• Pulse oximetry: Non-invasive measurement of blood oxygen saturation
• Electrocardiogram (ECG): To rule out heart problems that can cause similar symptoms

How Is Pneumothorax Treated?

Treatment depends on the size of the pneumothorax and symptom severity. Small pneumothorax may be observed with supplemental oxygen. Larger pneumothorax requires intervention to remove air - either needle aspiration or chest tube drainage. Recurrent cases may need surgery (VATS) with pleurodesis to prevent further episodes.

The treatment approach for pneumothorax depends on several factors: the size of the pneumothorax, the severity of symptoms, whether it is a first episode or recurrence, and whether there is underlying lung disease. The goals of treatment are to remove the accumulated air, allow the lung to re-expand, and prevent recurrence.

Observation and Oxygen Therapy

Small pneumothorax (typically less than 2cm from the chest wall to the lung edge) in stable patients without significant symptoms may be managed conservatively with observation. The body can gradually absorb the trapped air at a rate of approximately 1-2% of the hemithorax volume per day.

Supplemental oxygen therapy accelerates air absorption by creating a nitrogen gradient that helps the body absorb air from the pleural space more quickly. Patients are typically kept under observation in the hospital or returned for follow-up X-rays within 24-48 hours to ensure the pneumothorax is not enlarging.

Needle Aspiration

Needle aspiration is often the first-line treatment for moderate primary spontaneous pneumothorax. A needle is inserted into the pleural space (usually in the second intercostal space in the midclavicular line), and air is withdrawn using a syringe. This procedure can be performed at the bedside or in an emergency department.

Needle aspiration is successful in approximately 50-70% of primary spontaneous pneumothorax cases. If the lung does not re-expand after aspiration, or if the pneumothorax recurs quickly, chest tube drainage is typically required.

Chest Tube Drainage

Chest tube drainage (tube thoracostomy) is the standard treatment for large pneumothorax, failed needle aspiration, secondary spontaneous pneumothorax, and tension pneumothorax. A small tube is inserted between the ribs into the pleural space and connected to a one-way drainage system that allows air to escape but prevents it from re-entering.

The procedure is performed with local anesthesia. The tube is typically placed in the "safe triangle" of the chest wall - an area bounded by the lateral edge of the pectoralis major muscle, the lateral edge of the latissimus dorsi muscle, and a horizontal line at the level of the nipple. This location minimizes the risk of damaging major blood vessels or organs.

Once inserted, the tube is connected to an underwater seal drainage system. Air bubbling in the system indicates ongoing air leak from the lung. The tube remains in place until the lung has fully re-expanded and no air leak is present, usually for 2-5 days. Follow-up chest X-rays confirm successful treatment before the tube is removed.

Surgery for Recurrent Pneumothorax

Surgery is recommended for patients who have had recurrent pneumothorax, bilateral pneumothorax (both sides), or persistent air leak despite chest tube drainage. The goal of surgery is to remove blebs or bullae and to create adhesion between the lung surface and chest wall (pleurodesis), preventing future episodes.

Video-assisted thoracoscopic surgery (VATS) is the preferred surgical approach. This minimally invasive technique uses small incisions and a camera to visualize and treat the lung. During VATS, the surgeon can:

• Identify and remove blebs or bullae (bullectomy)
• Perform pleurodesis - either mechanical (pleural abrasion) or chemical (applying talc or other agents)
• Resect (remove) damaged portions of lung tissue if necessary

Surgery with pleurodesis reduces the recurrence rate to less than 5%, compared to 30-50% with conservative management alone. Recovery from VATS typically takes 1-2 weeks, and most patients can return to normal activities within a month.

Treatment Summary by Pneumothorax Type

What Are the Complications of Pneumothorax?

The main complications of pneumothorax include recurrence (30-50% risk after first episode), tension pneumothorax (life-threatening if not treated immediately), and rarely, bilateral pneumothorax (both lungs affected simultaneously). Proper treatment and smoking cessation significantly reduce complication risk.

Understanding potential complications helps patients recognize warning signs and appreciate the importance of follow-up care and lifestyle modifications.

Recurrence

The most common complication of pneumothorax is recurrence. After a first primary spontaneous pneumothorax, the risk of recurrence is approximately 30-50%, with most recurrences happening within the first two years. After a second episode, the recurrence risk increases to 60-80%, which is why surgery is often recommended after the second occurrence.

Factors that increase recurrence risk include:

• Continued smoking
• Presence of blebs or bullae on CT scan
• Younger age at first episode
• Tall, thin body type
• Female sex (higher recurrence rate than males)

Tension Pneumothorax

Tension pneumothorax occurs when air continues to enter the pleural space but cannot escape, creating progressively increasing pressure. This is a life-threatening emergency that can develop from any type of pneumothorax. The increasing pressure pushes the heart and major blood vessels to the opposite side (mediastinal shift), compromising blood circulation and potentially causing cardiac arrest.

Signs of tension pneumothorax include rapidly worsening symptoms, distended neck veins, tracheal deviation, and signs of shock (low blood pressure, rapid heart rate, confusion). Treatment involves immediate needle decompression followed by chest tube insertion.

Bilateral Pneumothorax

Bilateral pneumothorax, where both lungs are affected simultaneously, is rare but can be life-threatening as it severely compromises the body's ability to oxygenate blood. It can occur in patients with underlying lung disease such as LAM or in patients on mechanical ventilation.

Complications of Treatment

While treatment complications are uncommon, they can include:

• Pain at the chest tube insertion site
• Infection at the insertion site
• Bleeding
• Re-expansion pulmonary edema (rare, occurs when lung re-expands too quickly)
• Surgical complications (for VATS): wound infection, prolonged air leak, bleeding

How Can You Prevent Pneumothorax?

The most important prevention measure is smoking cessation, which reduces the risk by approximately 20-fold. People who have had pneumothorax should avoid activities with pressure changes (scuba diving, unpressurized aircraft) until cleared by a doctor. Surgery (VATS with pleurodesis) reduces recurrence risk to less than 5%.

While not all pneumothorax can be prevented, particularly those resulting from trauma or underlying lung disease, there are important steps to reduce the risk of first occurrence and recurrence.

Stop Smoking

Smoking cessation is by far the most important preventive measure. Smoking increases the risk of primary spontaneous pneumothorax by approximately 20 times in men and 9 times in women. The risk is dose-dependent - the more you smoke, the higher your risk.

Quitting smoking reduces the risk of both first and recurrent pneumothorax. If you have had a pneumothorax and continue to smoke, your risk of recurrence is significantly higher than if you quit. Stopping smoking also reduces the risk of developing other lung conditions that can cause secondary spontaneous pneumothorax.

Activity Restrictions After Pneumothorax

After recovering from a pneumothorax, certain activities should be avoided or approached with caution:

• Scuba diving: Generally contraindicated after pneumothorax unless the patient has had definitive surgical treatment (VATS with pleurodesis). The pressure changes during diving can trigger recurrence.
• Flying in unpressurized aircraft: Should be avoided for at least 2-6 weeks after pneumothorax resolves. Commercial pressurized flights are generally safe after the lung has fully re-expanded.
• High-altitude activities: Mountaineering and other high-altitude activities may increase risk.
• Contact sports: May need to be avoided initially after recovery.

Surgical Prevention of Recurrence

For patients who have had recurrent pneumothorax or who are at high risk of recurrence, surgery with pleurodesis is highly effective at preventing future episodes. This procedure creates adhesion between the lung and chest wall, preventing the lung from collapsing even if a bleb ruptures.

Surgery is typically recommended after:

• Second episode of pneumothorax on the same side
• First episode if the patient has a high-risk occupation or hobby (pilots, divers)
• First episode with bilateral pneumothorax
• Persistent air leak despite chest tube drainage

What Is the Prognosis for Pneumothorax?

Most people with pneumothorax recover completely with appropriate treatment. Small pneumothorax often resolves within 1-2 weeks with observation. After chest tube treatment, recovery typically takes 2-5 days in hospital followed by 1-2 weeks at home. The main concern is recurrence, which occurs in 30-50% of cases without surgery.

The overall prognosis for pneumothorax is generally excellent, particularly for primary spontaneous pneumothorax in otherwise healthy individuals. Most patients recover completely and return to their normal activities without long-term complications.

For primary spontaneous pneumothorax, the immediate recovery is usually straightforward. After treatment - whether observation, aspiration, or chest tube drainage - most patients are symptom-free within days to weeks. The lung typically re-expands fully, and lung function returns to normal.

For secondary spontaneous pneumothorax in patients with underlying lung disease, the prognosis depends largely on the severity of the underlying condition. While the pneumothorax itself can be treated, the patient's overall respiratory function may remain limited by their pre-existing disease. Mortality rates are higher in this group compared to primary spontaneous pneumothorax.

The long-term outlook is primarily influenced by the risk of recurrence. Without preventive surgery, the recurrence rate is substantial, but patients who undergo VATS with pleurodesis have excellent long-term outcomes with very low recurrence rates.