Written by Ada’s Medical Knowledge Team
What is a pneumothorax?
A pneumothorax, also sometimes referred to as a collapsed lung or punctured lung, is defined as the presence of air or other gas in the chest between the outside of the lungs and the inside of the chest wall. 
The lungs and the inside of the chest wall have a smooth lining known as the pleura, which allows the lungs to expand without chafing on the chest wall. Usually, the two layers of pleura have only a small space between them, known as the pleural cavity, filled with lubricating fluid. A pneumothorax occurs when air enters this space due to damage.
This air buildup leads to increased pressure on the affected lung and prevents it from being able to expand fully.
A pneumothorax usually occurs on one side of the chest, so most often leads to one of the lungs being affected.
Signs of a pneumothorax vary depending on the amount of lung area affected. While a small pneumothorax may sometimes be asymptomatic, i.e. not produce any symptoms, normally symptoms are experienced. They include a sudden, sharp chest pain, followed by shortness of breath, which may also be severe. An X-ray may be used to confirm the diagnosis.
A pneumothorax can sometimes occur without any particular cause. In such cases it is called a spontaneous pneumothorax. This occurs especially often in young, lean and tall men and is much more likely in heavy smokers. Other pneumothorax causes include injury to the chest, lung disease, being on a breathing machine, surgery to the chest or abdomen, or a blocked airway.
A small pneumothorax may occasionally not need any particular treatment, but a larger pneumothorax may need to have the air let out to help improve breathing and to allow the lung to expand again. This condition can lead to problems that may be life-threatening. However, with proper treatment most people recover from a pneumothorax without any substantial long-term problems..
- A sudden, sharp stabbing pain on one side of the chest, usually made worse by breathing in
- Shortness of breath
- A feeling of tightness in the chest
- A rapid heart rate
- Rapid breathing
- Feeling physically weak
- Blue fingers and lips
- Possibly collapse
Other symptoms may be present if a lung infection is the cause. These may include:
- A cough
- A high temperature or fever
Good to know: The more breathless you become, the larger the pneumothorax usually is. It is possible to have a smaller pneumothorax with only mild symptoms or, rarely, without symptoms. People with more severe symptoms of a pneumothorax, such as substantial shortness of breath, require emergency treatment in a hospital, and the person affected should be transported to a hospital in the quickest possible way, e.g. in an ambulance.
What causes a pneumothorax?
A pneumothorax is the presence of air between the two thin layers of membrane, known as the pleura, that cover the lungs and also line the inside of the chest wall, resulting in the collapse of one or even both lungs.
Normally, the pressure in the pleural space is lower than that of the atmosphere or inside the lungs. If there is a cut or tear that makes a connection between the pleural space and the inside of the lungs or the atmosphere, then air will enter the pleural space. This continues until the pressure equalizes or the connection closes. Air in the pleural space causes the lung to collapse partially or fully, leading to this lung or part of the lung being non-functional, causing shortness of breath.
- An injury to the chest, which could be from blunt force or from something penetrating the chest
- An underlying lung condition or lung infection
- An invasive medical procedure on the chest or abdomen
- Being on a breathing machine/ventilator due to treatment in hospital or a long-term care facility
Good to know: A pneumothorax can also occur with no particular cause. This is most common in young, thin males, especially if they are smokers.
Types of pneumothorax
There are two main types of pneumothorax:
Traumatic pneumothorax: This can be caused by an injury from blunt force or a penetrating object, or an invasive medical procedure, such as a lung biopsy.
Good to know: A traumatic pneumothorax may often be accompanied by a hemothorax, which is the accumulation of blood in the pleural space.
Spontaneous pneumothorax: Occurs without preceding injury, often without clear reason, but sometimes as a result of lung disease. It is usually due to a tiny tear in the lung, often at the site of a tiny balloon of tissue, known as a bleb or, if bigger, a bulla, that can develop on the edge of a lung. The bleb or bulla wall is not as strong as other lung tissue, so it is more likely to tear.
These two main types of pneumothorax may be further divided into four categories:
Primary spontaneous pneumothorax (PSP)
This is the most common type of spontaneous pneumothorax. It develops for no clear reason in an otherwise healthy person. Symptoms in PSP may be minimal or even absent.
- Being tall and thin, because of stretching of the body tissues
- Gender: Pneumothoraces occur more often in men
- Age: If a man, being in one’s 20s or, if a woman, being in one’s early 30s
- Family history of pneumothorax
- Smoking tobacco
- A previous pneumothorax
- Women with thoracic endometriosis, a rare form of endometriosis, where endometrial tissue is found in the lung and/or pleura
- Certain rare genetic conditions, such as Marfan syndrome, homocystinuria and Birt-Hogg-Dube syndrome
Secondary spontaneous pneumothorax (SSP)
This develops as a complication of an existing lung disease, particularly those which weaken the edge of the lung, making it more likely to tear.
Symptoms are normally more severe in SSP, even if the pneumothorax is relatively small in size: Due to pre-existing chronic lung disease, the lungs tend to have less reserve, i.e. less volume of air that they can inhale and exhale, when breathing to the limit of capacity in times of stress.
- Chronic obstructive pulmonary disease (COPD)
- Sarcoidosis, a rare condition that causes small patches of red and swollen tissue, usually in the lungs and skin
- Idiopathic pulmonary fibrosis, a condition in which tissues in the lung become thick and scarred over time
- Cystic fibrosis
- Lung cancer
Closed traumatic pneumothorax
Closed pneumothorax is caused by blunt trauma, such as in a car accident in which the thorax is impacted by the steering wheel. Air enters through a hole in the lung itself.
Open traumatic pneumothorax
Open pneumothorax, also known as a sucking chest wound, may occur after a penetrative injury, such as a gunshot or knife wound, when there is an unsealed opening in the chest wall.
This causes air to flow into the lungs through the normal breathing mechanism and simultaneously into the pleural space through the opening in the chest wall. This open pneumothorax may then lead to collapse of the affected side of the lung, with ventilation being practically eliminated on the affected side. 
Good to know: iatrogenic pneumothorax is an injury that occurs as a complication of medical or surgical procedures in the lung area, such as fitting a pacemaker or central venous line[^34] insertion, a lung biopsy, or CPR.
Some cases of iatrogenic pneumothorax are not very serious and do not require treatment, while others can lead to serious cases that may require emergency treatment.
Complications of pneumothorax
In many cases, a pneumothorax responds well to treatment or may even resolve on its own, healing from within a few days to a couple of weeks, depending on the cause and the severity of the pneumothorax. In some cases, more serious complications can occur.
In most cases of pneumothorax, some air can move in and out through the tear in the lung or chest wall. In some cases, more likely when a person is affected by open pneumothorax from penetrating chest injuries – though this is also possible in other forms of pneumothorax – air can move into the chest cavity, but not out, leading to a buildup of pressure inside the pocket of trapped air. This is known as a tension pneumothorax.
This can lead to compression of the neighboring lung and even push the heart and major blood vessels to the other side of the chest, which may lead to cardiac failure. A tension pneumothorax is a life-threatening emergency. If suspected, medical attention should be sought immediately, and the person affected should be transported to a hospital in the quickest possible way, e.g. in an ambulance.
- Chest pain
- Rapid heart rate
- Low blood pressure
- Rapid, distressed breathing
- Severe difficulty breathing
- An overly expanded chest that moves very little with breathing
- Secondary spontaneous pneumothorax, where there is underlying lung disease
- People who are on artificial/mechanical ventilation, where spontaneous breathing is assisted or replaced
- Pneumothorax as a result of trauma, especially penetrating trauma, such as a knife stab wound
- People who have been resuscitated after stopping breathing or after the heart stops working
- Blocked, clamped or displaced chest drains, normally used to allow draining of air, blood or fluid out of the pleural space
- People undergoing hyperbaric oxygen therapy, a treatment for decompression sickness, a hazard of scuba diving
Some people who have had one pneumothorax may have another, usually within one to two years of the first. Causes of recurrent pneumothorax may include:
- Rupture of further blebs
- Continued air leakage on the site of a previous pneumothorax
To reduce the possibility of blebs and recurrence of pneumothorax a person may:
- Stop smoking tobacco products, if they do so
- Avoid air travel, until a doctor says it is okay to do so
- Avoid diving, until a doctor says it okay to do so
A doctor may suspect a pneumothorax if a person suddenly develops shortness of breath or chest pain, especially after trauma to the chest. They may ask about the affected person’s medical history, including any previous or current smoking habits, and they may carry out a physical examination. Tests to confirm diagnosis may include:
A chest X-ray (CXR) is often the best and quickest way to confirm the presence of a pneumothorax, which will appear on the X-ray as a darker area on the chest, representing the additional air in the chest cavity.
Pneumothorax computed tomography (CT) scan
In cases where there is doubt about the location or presence of a pneumothorax or for people with extensive lung disease, a CT scan may be used to find a small collapsed area of a lung.
Pulse oximeter or blood test
A doctor may also measure the oxygen level in the blood with a handheld device called a pulse oximeter, or they may draw blood from the wrist to directly measure the oxygen and carbon dioxide levels in the arterial blood, i.e. blood that has just passed through the lungs. While this alone does not normally allow for a diagnosis, it helps to determine how severely affected the person is and may help in determining treatment options.
Pneumothorax treatment depends on the size of the air collection in the chest and the severity of the symptoms. A small pneumothorax may not require any particular treatment, as it may resolve on its own.
Pneumothorax chest tube
If the affected person is breathless, due to a larger pneumothorax or other lung or breathing problems, then the trapped air may need to be removed via a process known as needle decompression or needle aspiration.
This involves putting in a chest tube, inserted with the aid of a needle, after locally anesthetizing the area used for access. This tube then helps to release the trapped air: A person may then need to stay in hospital for a day or more for observation, to make sure the affected lung is inflating properly once again and is not at risk of collapsing again. The hospital stay time will depend on the injury, general condition of the affected person and any other medical conditions present.
In the case of tension pneumothorax, decompression is done as a matter of urgency. Some cases of pneumothorax may need to be treated by a tube remaining in place for a few days and applying continued suction, for example if there are frequent recurrences within a short time.
Sometimes pneumothorax happens again spontaneously. A person who has had repeated episodes of pneumothorax may be recommended surgery to prevent the condition from coming back again. It may also be recommended to anyone who has had a tension pneumothorax.
A lung specialist will be able to advise on the pros and cons of each procedure, according to each individual case of a pneumothorax. Pneumothorax surgery may include:
This is an operation to help stick the two membranes, known as pleura, that surround the lung back together. This may be done in two ways:
- Under local anesthetic, while the person is awake, through a chest drain tube
- **Under general anesthesia, with the person fully asleep, using keyhole surgery
- Chemical pleurodesis using an irritant powder, such as talc
- Rubbing with a rough pad, causing inflammation which makes the lung surface stick to the inside of the chest wall
This is the removal of part of the pleura that surrounds the lung and lines the inner chest cavity, so that the lung sticks to the inside of the chest wall. It may also be combined with the other methods mentioned here.
This is the removal of blebs or bullae, weakened sac-like areas on the lung surface that are more likely to rupture.
Pneumothorax recovery time
A very small pneumothorax in a healthy adult may heal within a few days without treatment. Otherwise, recovery generally takes from one to a few weeks.
Good to know: It is important to avoid flying or diving until after a person has been given the all-clear from their doctor, as the change in pressure can worsen a pneumothorax.
Measures to aid recovery time include:
- Avoiding smoking tobacco
- Avoiding talking loudly and laughing
- Breathing exercises if recommended by a doctor
- Taking a cough suppressant if recommended by a doctor
Pneumothorax in newborns
Rarely, pneumothorax can occur in newborn babies when some of the tiny air sacs, known as alveoli, in a baby’s lung become overinflated and burst.
Respiratory distress syndrome (RDS) is the most common cause of pneumothorax in a newborn. This is a rare condition that occurs more commonly in babies born extremely premature. In cases of respiratory distress syndrome, the lungs are stiff and lack surfactant, the slippery substance that helps them stay inflated, meaning they are not able to expand as easily.
Good to know: There are certain medications that can decrease the risk of RDS. If a premature birth is anticipated and cannot be delayed any further, then substances such as corticosteroids may be given to the mother to promote the baby’s lung development. An artificial surfactant can also be given to the baby, preferably within the first few hours after birth.
Meconium aspiration syndrome is a condition in which, before or during birth, the baby may breathe in its first bowel movement, which can obstruct the airways and cause breathing problems.
The use of continuous positive airway pressure (CPAP), a technique that allows newborns to breathe on their own while receiving slightly pressurized oxygen, or a breathing machine is sometimes necessary to support a newborn. The air pressure will be carefully regulated to avoid pneumothorax. However, it can occasionally still occur due to the extra pressure on the baby’s lungs, which can burst the air sacs. Health care providers will watch a baby carefully for any signs of pneumothorax, so that, if it occurs, treatment can be started as quickly as possible.
Rarely, other conditions that affect the lungs, such as pediatric pneumonia may also lead to neonatal pneumothorax.
Very rarely, even an otherwise healthy infant can develop a pneumothorax when he or she takes the first few breaths after birth, as the pressure needed to expand the lungs for the first time may in very rare cases be enough to cause a rupture.
- Fast breathing and grunting
- Nostril flaring
- Indrawing of the skin in between each rib and indrawing of the stomach just below the rib cage
- Chest appears markedly larger on one side than on the other
- Low oxygen saturation of the blood resulting in bluish skin color
- Irritability/excessive crying or crying that is different from usual
- Difficulty feeding the baby
Supplementing oxygen: The infant is placed inside a small tent, known as an oxygen hood, into which oxygen is pumped.
Draining collected air with a syringe or a chest tube: If the newborn’s breathing is labored, or if their blood levels of oxygen decline, trapped air may need to be removed using a needle and syringe or, in more serious cases, using a plastic tube which stays in place temporarily and is removed after a few days.
If the pneumothorax is an isolated event and is treated quickly, the prognosis or outcome is normally good. Long term lung damage is rare. If other trauma was sustained at the same time or tension pneumothorax occurred with subsequent shock and inadequate blood flow to the body tissues, the prognosis may worsen. An affected infant will most likely also need regular follow-up clinic appointments. It is important to adhere closely to the doctor’s recommendations during the stay and when discharged from the hospital.[^27]
Q: Atelectasis vs pneumothorax - what is the difference?
A: Both a pneumothorax and an atelectasis may commonly be referred to as collapsed lung, however, they are separate conditions. They may both affect one entire lung or only a part of a lung. A pneumothorax leads to collapse of a lung when air escapes from the lung and fills the space between the lung and the chest wall, or air enters the chest from the outside, e.g. after a penetrating injury to the chest. Atelectasis collapse occurs because of a blockage, most often of the lower or smaller branches of the lung air passages, or by pressure on the outside of the lung. Blockages and pressure changes leading to atelectasis may, for instance, be caused by:
- A mucus plug
- A tumor
- An inhaled foreign object
- Lung disease
Q: Pneumothorax vs tension pneumothorax - what is the difference?
A: Pneumothorax is the accumulation of air between the lungs and the chest walls in the pleural space. In a normal pneumothorax, a certain amount of air enters the pleural space, and then stops accumulating. In a tension pneumothorax, air continues to enter the pleural space as the person breathes and pressure rises inside the chest. This reduces the amount of blood returned to the heart, as the blood cannot force its way against the increased pressure from the tension pneumothorax into the vessels running through the chest and back to the heart. As a result, the heart has less blood to pump through the body and to the brain, possibly resulting in shock.
Good to know: A tension pneumothorax is a severe, life-threatening form of pneumothorax requiring immediate medical intervention. These effects may often occur rapidly and need to be resolved as quickly as possible to minimize any harmful effects.
Q: Hemothorax vs pneumothorax
A: While a pneumothorax is an accumulation of air between the lung and the chest wall in the pleural space, a hemothorax is an accumulation of blood in the pleural space. A hemothorax usually results from injury, blunt or penetrating, that cuts a lung or an artery, or a vein in the chest, but may also occur with chest surgery or bleeding caused by a condition such as lung cancer or tuberculosis. If a large amount of blood pools, it may press on the lungs and make breathing difficult. A pneumothorax can occur together with a hemothorax, which is then known as a hemopneumothorax.
Q: Can a pneumothorax heal itself?
A: Yes, it is possible for a small pneumothorax to heal on its own without treatment. In such cases, a person may only require oxygen and rest to make a full recovery. However, if pneumothorax is causing considerable breathlessness, it is likely that the trapped air may need to be drained using a needle and syringe or via a chest tube.
Good to know: In cases of tension pneumothorax, immediate, life-saving medical attention and emergency treatment in a hospital are required.
Other names sometimes used for pneumothorax
- Collapsed lung
- Punctured lung
Medscape eMedicine. ["Pneumothorax Clinical Presentation."]https://emedicine.medscape.com/article/424547-clinical) 11 December 2017. Accessed 26 August 2018. ↩
GP Notebook. "patient advice following spontaneous pneumothorax." Accessed 26 August 2018. ↩
BMJ Best Practice. "Pneumothorax - Symptoms, diagnosis and treatment." Accessed 24 August 2018. ↩
Emedicine Medscape. "Pleurectomy Technique: Pleurectomy for Pneumothorax." 15 September 2015. Accessed 12 November 2018. ↩
The MSD Manuals. "Pneumothorax in the Newborn - Children's Health Issues." Accessed 26 August 2018. ↩ ↩ ↩
Northwestern Medicine. "Atelectasis and Pneumothorax Causes and Diagnoses." Accessed 26 August 2018. ↩
The MSD Manuals. "Tension Pneumothorax." Accessed 26 August 2018. [^34] A central venous line is a very thin, tube-shaped medical device that runs through the veins to the heart, used by doctors to access the venous system, which transports deoxygenated blood from the body back to the heart, to administer drugs, nutrition, fluids and to monitor blood pressure. ↩