What Is Catamenial Pneumothorax?


Catamenial pneumothorax (CP) is a rare condition categorised by ​the presence of air in the​ pleural cavity outside the lungs (pneumothorax) just before menstruation. It occurs in people who menstruate during their reproductive years. Its definition varies depending on how the term  "perimenstrual period" is defined, which normally covers the 72 hours prior to and following menstrual flow. Pneumothorax occurs when there is an accumulation of air ​between the parietal and​ ​visceral pleura of the chest​ wall and lungs, which ​can put​ ​pressure on the lung and cause it to collapse.2 

Understanding catamenial pneumothorax  

CP can be described as the repeated presence of air in the pleural cavity in menstruating people who have not been diagnosed with lung disease. The diagnosis of the condition requires that it should occur within 72 hours of your monthly menstruation.1 

Other features required for diagnosis include experiencing pneumothorax on the right side, pleural injury, and the presence of intra-thoracic endometriosis.  Medical literature often refers to CP as a “pneumothorax linked with menstruation” or “pneumothorax associated with menstruation”. 

Intrathoracic endometriosis can occur during catamenial pneumothorax; though the link between these two conditions is not completely clear, reports show it is occurring in 73% of CP cases.1 When endometrial tissue starts to grow in the chest cavity, it could be a case of intrathoracic endometriosis. It has been reported to occur during ovulation and early pregnancy.4,5 Also, an increase in the serum level of the Ca125 antigen is an indicator of the presence of both endometriosis and catamenial pneumothorax.6 

Symptoms and diagnosis  

Common signs and symptoms of catamenial pneumothorax  

The symptoms of catamenial pneumothorax coincide with those of pneumothorax but can occasionally be asymptomatic.2 Symptoms include:  

  • Severe chest pain  
  • Tachycardia (increased heart rate) of over 134 beats per minute  
  • Cardiac arrest 
  • Low blood pressure  
  • Cyanosis (bluish hand and lips due to lack of blood oxygen)  
  • Respiratory failure  
  • Dyspnoea (shortness of breath)  
  • Fatigue  
  • Dry cough 


There are no specified criteria for the diagnosis of CP. However, during radiological examination for other conditions like pneumoperitoneum, CP might be suspected with associated right-side pneumothorax. Other diagnostic criteria include diaphragmatic defects that may include the liver, diaphragmatic hernia, or perforated diaphragm known as “air-filled bubbles”.7,8 Although diagnosis is commonly done through chest x-rays; chest radiography and computed tomography are also used. 

Importance of medical evaluation and imaging tests 

Sometimes, CP is detected during examination for pelvic endometriosis. This is also due to the link between pelvic and intrathoracic endometriosis. It is important to undergo extensive checkups during diagnostic evaluation for related disease conditions mentioned above.1 

Causes and risk factors  

Endometrial tissue enters the chest cavity  

The specific cause of CP is not known, but it is suspected to be associated with pelvic endometriosis. However, no link has been established between these two conditions. The explanation given to explain the suggested association between the two conditions is the movement of endometrial cells through the lesser pelvis into the diaphragm area, causing injury to the diaphragm.7 

Hormonal changes during menstruation contribute to lung issues

High levels of prostaglandin during menstruation could result in blood vessel and bronchiole contraction, causing the alveoli to rupture and resulting in pneumothorax.1  

Treatment and management  

To treat CP, video-assisted thoracoscopic surgery (VATS) is the most commonly used procedure. In the case of recurrence after VATS, it is advised that the patients undergo a thoracotomy. If, after thoracotomy, the patient has major diaphragmatic lesions, the use of video-assisted mini-thoracotomy is advised.9 Pleurectomy and bullectomy have also been suggested as appropriate interventions.10 

Another debate is how much reconstruction should be done inside the diaphragm, especially if there are no diaphragmatic defects present. It has been advised that any person of menstrual age who has undergone a pneumothorax surgery should have a thorough pulmonary assessment for damage detection. 

In situations where both CP and endometriosis are present, it is advised that surgery should take the place of hormonal therapy, given the low chance of recurrence post-surgery.11  

Approaches to managing acute episodes of catamenial pneumothorax 

There is no strict guidance for the management of CP and avoiding its recurrence. In the case of an emergency, pneumothorax decompression is a preferred therapeutic option. Hormonal therapy and surgical treatment have varying degrees of effectiveness in preventing recurrence. Each form of treatment has its drawbacks and cannot guarantee total efficacy. 

A gynaecologist can decide to treat the endometriosis if that is an underlying condition. This usually involves hormonal treatment targeted towards inducing hypoestrogenism. However, several precautions need to be in place to achieve effective treatment without a negative impact on reproductive health and fertility.  

Prognosis and long-term outlook 

Care for patients with CP involves a multidisciplinary team due to the multiple requirements of the therapies involved: its chronic course, the need for surgical interventions in various body cavities or long-term medications, and the relatively unpredictable nature of the treatment results. Given the potential risk of having concurrent uterine endometriosis, patients with this condition are also advised to seek gynaecological evaluation.1


Catamenial pneumothorax is prevalent among people in their menstrual years. As a young person diagnosed with pneumothorax, it is important to be attentive during the peri-menstrual phase in the case of any unusual symptoms. Treatment failure can occur and result in recurrence of the condition, but surgical removal of lesions around the parietal and visceral pleural membranes can help to curb this. 

All the treatment options discussed above have shown potential in the management of the condition. Ensure that you visit a healthcare provider in the case of suspected illness and partake in all the treatment and management procedures that have been arranged by the healthcare provider. Although catamenial pneumothorax is a rare condition, the similarity of its symptoms with pneumothorax has made more treatment accessible.   


  1. Marjański T, Sowa K, Czapla A, Rzyman W. Catamenial pneumothorax - a review of the literature. Kardiochir Torakochirurgia Pol. 2016;13(2):117-21. 
  2. McKnight CL, Burns B. Pneumothorax.  StatPearls. Treasure Island (FL): StatPearls Publishing  Copyright © 2023, StatPearls Publishing LLC.; 2023. 4. Channabasavaiah AD, Joseph JV. Thoracic endometriosis: revisiting the association between clinical presentation and thoracic pathology based on thoracoscopic findings in 110 patients. Medicine (Baltimore). 2010;89(3):183-8. 
  3. Yoshioka H, Fukui T, Mori S, Usami N, Nagasaka T, Yokoi K. Catamenial pneumothorax in a pregnant patient. Jpn J Thorac Cardiovasc Surg. 2005;53(5):280-2. 
  4. Bagan P, Berna P, Assouad J, Hupertan V, Le Pimpec Barthes F, Riquet M. Value of cancer antigen 125 for diagnosis of pleural endometriosis in females with recurrent pneumothorax. Eur Respir J. 2008;31(1):140-2. 
  5. Downey DB, Towers MJ, Poon PY, Thomas P. Pneumoperitoneum with catamenial pneumothorax. AJR Am J Roentgenol. 1990;155(1):29-30. 
  6. Bobbio A, Carbognani P, Ampollini L, Rusca M. Diaphragmatic laceration, partial liver herniation and catamenial pneumothorax. Asian Cardiovasc Thorac Ann. 2007;15(3):249-51. 
  7. Cieslik L, Haider SS, Fisal L, Rahmaan JA, Sachithanandan A. Minimally invasive thoracoscopic mesh repair of diaphragmatic fenestrations for catamenial pneumothorax due to likely thoracic endometriosis: a case report. Med J Malaysia. 2013;68(4):366-7. 
  8. Alifano M, Legras A, Rousset-Jablonski C, Bobbio A, Magdeleinat P, Damotte D, et al. Pneumothorax recurrence after surgery in women: clinicopathologic characteristics and management. Ann Thorac Surg. 2011;92(1):322-6. 
  9. Joseph J, Sahn SA. Thoracic endometriosis syndrome: new observations from an analysis of 110 cases. Am J Med. 1996;100(2):164-70. 
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Oluwanifesimi Ayo Adewale

MSc Biomedical Science, University of Chester

Oluwanifesimi is a first- class graduate of human anatomy with a passion for teaching and medical research. Through her academic and professional career, she has worked on different research projects including an umbrella project with the NHS. Owing to her expertise in research and education, she has developed an aptitude for conveying scientific information accurately. Her goal is to prevent inaccurate dissemination of medical information by writing concise and clear articles for specific audiences

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