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You suspect you may have endometriosis or adenomyosis

What is catamenial pneumothorax?

Topic:Deep Disease
Affected areas:chestsystemicabdominal

Catamenial pneumothorax is a collapsed lung that happens in a repeating pattern around your menstrual period—most often just before or during bleeding. It’s considered part of thoracic endometriosis syndrome, where endometriosis affects the diaphragm, chest cavity, or (more rarely) lung tissue.


People may notice sudden one-sided chest pain, shortness of breath, or a “recurring pneumothorax” that seems to return month after month. Because routine imaging can confirm the lung collapse but not always reveal the cause, the menstrual timing is an important clue. If your chest symptoms track your cycle—especially with a history of suspected or known endometriosis—our team can help connect the dots and discuss next steps for evaluation and treatment options.

An illustration of 3 silhouetted women each showing discomfort in areas of the pelvis.

Think You Might Have Endometriosis?

If you suspect endometriosis or adenomyosis may be causing your symptoms, our specialists can provide expert evaluation and guidance on next steps.

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Dr. Steven Vasilev delivers best-in-class endometriosis guidance and a personalized treatment plan—built on evidence and your unique biology.


Led by Steven Vasilev, MD—an internationally recognized endometriosis specialist & MIGS surgeon—Lotus Endometriosis Institute is virtual-forward, with many patients traveling nationally for care. Clinical evaluation and surgical treatment are provided in California.

Santa Monica, CA

2121 Santa Monica Blvd, Santa Monica, CA 90404

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Monday - Friday

Arroyo Grande, CA

154 Traffic Way, Arroyo Grande, CA 93420