What Is Catamenial Pneumothorax?

Table of Contents
View All
Table of Contents

Catamenial pneumothorax is a rare condition that affects the membranes surrounding the lungs. It only occurs in people who have a menstrual cycle. A pneumothorax is a collection of air in the pleura (the space between the lungs and the wall of the chest), which causes one or both lungs to collapse. "Catamenial" is a medical term used to designate signs, symptoms, or conditions that only occur when a person is having a menstrual period.

Female patient receiving MRI scan
skynesher / Getty Images

Catamenial Pneumothorax Symptoms

Pneumothorax can cause sudden chest pain, which can be quite severe if the lung has collapsed.

Other signs and symptoms of pneumothorax include:

People who have catamenial pneumothorax often have a specific pattern to the timing of the symptoms, which can help differentiate the condition from pneumothorax caused by something else.

Additional symptoms associated with catamenial pneumothorax include:

  • Dry cough
  • Dizziness and fatigue
  • Crackling sound when taking a breath
  • Lung collapse within 72 hours of the onset of a menstrual period
  • Recurrent episodes of pneumothorax that happen monthly or in conjunction with a person's menstrual cycle
  • Chest pain that comes and goes on a monthly basis in accordance with the menstrual cycle


Pneumothorax is often caused by an injury or trauma to the chest, like what a person might sustain in a car accident. Pneumothorax can also occur spontaneously (without an obvious cause). The exact cause of catamenial pneumothorax is unknown.

Many documented cases of catamenial pneumothorax occurred in people with endometriosis. However, cases of catamenial pneumothorax have also been diagnosed in people who do not have endometriosis.


Endometriosis is when a type of tissue that is similar to the lining of the uterus is implanted in other parts of the body, often in the organs closest to the uterus, such as the fallopian tubes, ovaries, and the pelvic cavity. But it can implant elsewhere—including the chest cavity.

No matter where this tissue becomes implanted, it responds to the body's hormonal cues the same way as the lining of the uterus—meaning it bleeds each month. Unlike tissue found in the uterus, the blood from these extra-uterine lesions cannot leave the body. Instead, it causes inflammation and scarring.

Sometimes, endometriosis can be difficult to diagnose. A person may not realize they have endometriosis even if they are experiencing symptoms. Some people with endometriosis do not experience symptoms. Others may not realize the symptoms they experience are not normal.

Catamenial pneumothorax is believed to be caused when lesions of endometriosis become implanted in the pleura of the chest. When a person has a menstrual period, the tissue bleeds and forms cysts in the thoracic cavity. When blood, rather than air, leaks into the space between the chest wall and the lungs, the condition is referred to as hemothorax.

If you have a history of endometriosis and symptoms of pneumothorax, your healthcare provider may recognize catamenial pneumothorax as the cause.

Other Theories

A few other theories have been suggested as potential causes of catamenial pneumothorax.

Blebs, small pockets of air formed by damaged alveoli that can appear on the lungs, may burst in response to changes in hormone levels throughout the menstrual cycle. When blebs rupture, the air that escapes may find its way into the pleural space and cause symptoms.

It has also been suggested that during menstruation, air may be released from the reproductive organs into the chest cavity via the diaphragm.


Catamenial pneumothorax typically occurs in females of reproductive age. It is considered to be rare. Interestingly, it seems to happen most frequently on the right side of the chest, though the reason for this is not clear.

Certain signs or symptoms, such as respiratory symptoms or lung collapse that recur during the menstrual cycle, may make a healthcare provider suspect catamenial pneumothorax as the cause.

Many people who are ultimately diagnosed with catamenial pneumothorax are first diagnosed with a collapsed lung.

History and Physical Examination

Your healthcare provider will evaluate your condition in several ways. They will start by asking you questions about your current symptoms, as well as how your health has been in the past, and about any health problems that run in your family.

You may be asked questions about your lifestyle, such as if you smoke, drink, and get regular exercise, and about any medications you take, including over-the-counter medicine, vitamins, or health supplements.

Your healthcare provider will take your temperature, measure your pulse and blood pressure, and ask you to rate your pain on a numerical scale.

During your physical exam, your healthcare provider will place a stethoscope on your chest or back to listen to your breath sounds or use their hands to feel your belly. Let them know if you experience pain as they perform the exam.

Laboratory Tests

Other types of tests may be needed to investigate your symptoms. You might have a pulse oximetry test or an arterial blood gas to evaluate your oxygen level.


Your healthcare provider might send you to the radiology department to have an imaging test, such as an X-ray or computerized tomography (CT) scan. This may show a pneumothorax or another problem in the chest, such as signs of an infection.


You might need to have a minimally-invasive procedure called video-assisted thoracoscopy (VAT), which uses a small camera to look inside your chest cavity. During the procedure, the surgeon may be able to see lesions or blood.

They may also take a biopsy (a small tissue sample to be tested). If the biopsy appears to be endometrial-like tissue, this can confirm a diagnosis of thoracic endometriosis—which is a risk factor for catamenial pneumothorax.


There are several treatment options available for catamenial pneumothorax. In most cases, a combination of treatments is required to manage the condition.

Many people who experience catamenial pneumothorax often have minor episodes that seem to get better on their own without treatment. However, the condition may become more serious over time if it isn't treated.

Without treatment, the underlying condition causing catamenial pneumothorax, such as endometriosis, can get worse.

Emergency Treatment

An acute pneumothorax requires emergency medical care.

A tension pneumothorax or a collapsed lung that presses on structures surrounding the heart is a medical emergency, and it can be fatal without treatment. The treatment may involve aspiration, which is the insertion of a tube in the chest to free any trapped air or blood.

When the condition becomes chronic, as can happen with catamenial pneumothorax, the treatment will depend on the underlying cause and may not always require emergency medical intervention.

Endometriosis Treatment

If a catamenial pneumothorax is caused by a hormonally-driven condition like endometriosis, a healthcare provider may recommend is hormonal therapy.

Options like continuous birth control pills or GnRH antagonists (such as Lupron) can be used to control symptoms by suppressing the menstrual cycle. However, it should be noted that medications such as Lupron are not intended to be used long-term. Additionally, some people cannot safely take hormonal birth control pills due to underlying conditions, such as a heightened risk of blood clots.

If a catamenial pneumothorax is linked to endometriosis, surgery may be considered so a surgeon can remove any lesions or blood in the chest cavity.

Surgery can be done laparoscopically or as an open procedure:

  • During a laparoscopic procedure, the surgeon will make a few small incisions through which they can insert a camera and tools to remove the endometrial tissue. Compared to open surgery, people usually heal quicker and have fewer complications with laparoscopic surgery.
  • If the case is complicated or if there are many lesions, a surgeon may have to use traditional open surgery methods instead. Sometimes, parts of the diaphragm or lung may need to be resected (removed).

Pleurodesis and Pleural Abrasion

With pleurodesis, medication is used to cause inflammation in the lining of the chest cavity. The body responds to inflammation by creating scar tissue, which covers up holes that may have formed.

If the medication does not cause enough inflammation, a surgical procedure called pleural abrasion may be necessary. During this surgery, the surgeon rubs the inside of the chest cavity to directly cause inflammation. A surgeon may also put a type of dissolvable surgical mesh on the tissue of the diaphragm to help cover up any holes.

If you decide to have surgery, your medical team will discuss these possibilities with you and make sure you understand the risks and benefits.

A Word From Verywell

Catamenial pneumothorax is a rare condition affecting people who have a menstrual cycle. While the condition is uncommon, without treatment it can have serious consequences and seriously impact quality of life. The diagnosis of catamenial pneumothorax can be tricky, and it is considered when a person experiences respiratory symptoms that sync up with their menstrual cycle. The treatment will depend on the underlying cause of the condition and can include hormonal therapy, surgery, or both.

3 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. National Organization for Rare Disorders Catamenial pneumothorax.

  2. Gil Y, Tulandi T. Diagnosis and treatment of catamenial pneumothorax: A systematic reviewJ Minim Invasive Gynecol. 2020;27(1):48‐53. doi:10.1016/j.jmig.2019.08.005

  3. Visouli AN, Darwiche K, Mpakas A, et al. Catamenial pneumothorax: A rare entity? Report of 5 cases and review of the literatureJ Thorac Dis. 2012;4 Suppl 1(Suppl 1):17‐31. doi:10.3978/j.issn.2072-1439.2012.s006

Additional Reading
  • Peikert T, Gillespie DJ, Cassivi SD. Catamenial pneumothoraxMayo Clinic Proceedings. 2005;80(5):677-680. doi:10.4065/80.5.677

By Abby Norman
Abby Norman is a freelance science writer and medical editor. She is also the author of "Ask Me About My Uterus: A Quest to Make Doctors Believe in Women's Pain."