Chest pain, breathlessness, shoulder pain, or a lung that keeps collapsing — and it happens every month around the same time as your period. This is not a coincidence. It is a recognised condition called thoracic endometriosis syndrome, and it has a specific, treatable cause. Published research shows the average diagnostic delay is 5 to 12 years, mainly because the connection to the menstrual cycle is not made. Dr Lawrence Okiror, Consultant Thoracic and Robotic Surgeon (GMC 6150382), works closely with gynaecology colleagues at Guy’s and St Thomas’ to manage not just the chest disease, but all sites of endometriosis. Private appointments within 2–3 days. No GP referral required.
Last reviewed: April 2026 · Dr Lawrence Okiror FRCS(CTh) FRCSEd(CTh) · GMC 6150382
Published systematic reviews show that endometriosis takes an average of 5 to 12 years to diagnose from first symptoms. For thoracic endometriosis, the delay is often longer still — because the connection to the menstrual cycle is the clue most often missed.
Up to 80% of patients with thoracic endometriosis also have pelvic disease. Dr Okiror works with gynaecology colleagues at GSTT to provide joined-up management — thoracic surgery and gynaecological care coordinated as a whole, not treated in separate silos.
Keyhole thoracoscopy treats the thoracic disease at a single procedure. Combined with hormonal management, published data shows no recurrence in follow-up of up to 45 months. The years of recurring symptoms can stop.
If yes — if the chest pain, breathlessness, shoulder pain, or collapsed lung happens within one to three days of the start of your period, and improves after it ends — that is the diagnostic clue. If no one has yet connected this pattern to your chest symptoms, a thoracic surgical assessment is the appropriate next step. You should not have to go on managing recurring symptoms without an answer.
5–12
Years average diagnostic delay
Source: BJOG systematic review, 2024
72%
Of thoracic endometriosis presentations are a collapsed lung (catamenial pneumothorax)
80%
Also have concurrent pelvic endometriosis requiring gynaecological management
Chest pain that comes back at the same point of every cycle is a recognised pattern of thoracic endometriosis. Endometrial tissue on the pleura or diaphragm responds to the same hormonal changes as pelvic endometriosis, causing symptoms during menstruation and resolving between periods. It is frequently put down to musculoskeletal pain or anxiety. It has a specific cause, a specific investigation, and a definitive treatment.
Yes. A collapsed lung occurring within 72 hours of the start of a period is a recognised form of thoracic endometriosis called catamenial pneumothorax. It accounts for 72% of all thoracic endometriosis presentations and is the most frequently misdiagnosed. If you are a woman of reproductive age with more than one collapsed lung, the timing in relation to your period must be established. Pneumothorax page →
Yes. Up to 80% of patients with thoracic endometriosis also have pelvic disease, and pelvic endometriosis is thought to develop 5 to 7 years before thoracic symptoms appear. If you have confirmed pelvic endometriosis and are experiencing chest symptoms that worsen around your period, a thoracic surgical assessment is appropriate and worth pursuing.
Dr Okiror works closely with gynaecology colleagues at GSTT to provide joined-up management — not just the chest disease, but all sites of endometriosis. Surgery to treat the thoracic deposits is coordinated with gynaecological care and hormonal management. Patients are not left with only their chest symptoms addressed. Full thoracic endometriosis page →
There are four main ways thoracic endometriosis syndrome presents. All share the same clue: symptoms that follow a cyclical pattern in relation to the menstrual cycle.
Most Common — 72% of Cases
A lung that collapses within 72 hours of the start of menstruation. Usually right-sided. Caused by small holes in the diaphragm that allow air to pass from the abdomen into the chest. Recurs with every period until surgically repaired. The pattern — once identified — makes the diagnosis clear. Keyhole surgery repairs the defects and treats the deposits in a single procedure.
Chest Pain at Your Period
Chest pain or breathlessness that appears at menstruation and clears between periods. Caused by endometrial deposits on the lining of the lung (the pleura) that bleed during menstruation. Frequently attributed to musculoskeletal pain or anxiety. Keyhole surgery confirms the deposits visually and removes them at the same procedure.
Shoulder Pain at Your Period
Pain in the right shoulder tip that occurs at menstruation is caused by endometrial deposits on the diaphragm. The diaphragm and the right shoulder tip share a nerve (the phrenic nerve), so diaphragm irritation is felt as shoulder pain. Often mistaken for a shoulder or neck problem. Surgery removes the deposits and repairs the diaphragm. Diaphragm page →
Rarest Presentation
The rarest presentation: coughing up blood that coincides precisely with menstruation each month. Caused by endometrial deposits inside the lung tissue itself. CT or MRI will often show nodules that appear and resolve with the cycle. This is a rare presentation and is frequently missed or attributed to other causes. Specialist assessment is essential.
Treating thoracic endometriosis without addressing the underlying disease and any concurrent pelvic endometriosis is incomplete. Published data shows that surgery combined with hormonal suppression gives no recurrence in follow-up of up to 45 months — compared to a significantly higher recurrence risk with surgery alone.
Dr Okiror works closely with gynaecology colleagues at Guy’s and St Thomas’ NHS Foundation Trust. Patients presenting with thoracic endometriosis are assessed as a whole — the thoracic surgery, gynaecological management of pelvic and other sites of disease, and the hormonal management plan are coordinated together, at the same institution, without patients having to navigate between separate teams.
Questions most commonly asked by women experiencing chest symptoms that coincide with their menstrual cycle.
Book an Assessment →Or call Jo Mitchelson:
020 7952 2882
No GP referral required. Private appointments at London Bridge Hospital within 2–3 days. If your chest symptoms follow a cyclical pattern, a specialist assessment will establish whether thoracic endometriosis is the cause — and provide a clear plan for both the chest and the underlying disease.
Jo Mitchelson, Private PA · 020 7952 2882 · pa@lungsurgeon.co.uk
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