Chest Pain During Period: Causes and Thoracic Endometriosis

Chest pain during your period has many possible causes, and many of them are common, such as a strained chest muscle, heartburn or anxiety. One rare cause is thoracic endometriosis, where endometriosis grows in the chest and can cause chest pain, shortness of breath or coughing up blood around your period.

This guide covers when to get help at once, the other causes, the pattern that points to thoracic endometriosis, how doctors look into it, the treatments, and what to track before your appointment. It is general information and not medical advice.

When to get urgent help

Call 999 in the UK, 911 in the US, or your local emergency number, if you have:

• sudden chest pain that does not go away
• chest pain that spreads to your arm, neck, jaw, stomach or back
• chest pain with sweating, feeling sick, light-headedness or shortness of breath
• more than a few spots or streaks of blood when you cough, or blood with breathing problems, a very fast heartbeat, or chest or upper back pain

If you cough up only a few small streaks of blood, get an urgent GP appointment or call NHS 111 (or your own doctor or urgent care line). Do not wait for your period to end to see if it stops.

If your chest pain comes and goes, or goes away quickly but still worries you, see your GP.

Common causes of chest pain around a period

Common causes of chest pain around a period include:

Breast pain that changes with your cycle is very common. Our guide to breast pain after your period explains the usual pattern and the signs to get checked.

Costochondritis is inflammation where your ribs join your breastbone. The pain can get worse when you press on your chest or breathe deeply.

Anxiety, panic attacks, chest strains and heartburn are other common causes.

What thoracic endometriosis is

Endometriosis is when tissue similar to the lining of the womb grows outside the womb. It is usually in the pelvis, but sometimes it is found in the chest. When it is on the lung, on the lining around the lung (the pleura) or on the diaphragm, doctors call it thoracic endometriosis syndrome.

It is rare. Endometriosis on the diaphragm is found in about 0.19% to 1.5% of people with pelvic endometriosis, and it often causes no symptoms. People with thoracic endometriosis are diagnosed at an average age of about 35.

Signs that point to thoracic endometriosis

The main clue is timing. The symptoms usually line up with your period, although this is not always the case.

The signs are:

• A collapsed lung around your period (catamenial pneumothorax). This is the most common sign. In a review of 592 people with thoracic endometriosis, 68.4% had a collapsed lung linked to their period. It usually happens from 24 hours before to 72 hours after a period starts.
• Chest pain and shortness of breath. In the same review, 22% had chest pain and 20.9% had shortness of breath.
• Coughing up blood around your period. 14.2% coughed up blood.
• Shoulder, neck or upper belly pain. Endometriosis on the diaphragm can irritate the nerve that runs from the diaphragm, so you feel the pain in the shoulder, neck, shoulder blade or upper right belly, often in a cycle.
• Mostly on the right side. The right side of the chest is involved in about 90% of cases.

Pain on the right side that comes back with each period is worth telling a doctor about, even if it is mild. It is one of the rarer symptoms of endometriosis, so doctors may not think of it unless you point out the timing.

How doctors look into it

The diagnosis starts with your history, especially whether your symptoms line up with your period. A doctor will also ask about pelvic pain and other endometriosis symptoms.

Notes on which cycle days your chest or shoulder hurts help a doctor see the pattern.

Tests can include:

• A chest X-ray or CT scan. These are the usual first tests for a collapsed lung.
• Scans at different times of the month. Scans during your period and in the middle of your cycle can show changes that one scan alone may miss.
• An MRI of the chest and abdomen. This is often the best scan before surgery.
• Keyhole surgery of the chest (thoracoscopy, or VATS). A surgeon looks inside the chest with a camera and can take a sample. In the large review, 24.3% of cases were confirmed by finding endometriosis tissue.

Diagnosis is often slow. There can be about 19 months between the first collapsed lung and the diagnosis. Care works best with a team: a review recommends both a gynaecologist and a chest (thoracic) surgeon check you, and see you together after surgery.

Because thoracic endometriosis often comes with endometriosis in the pelvis, your gynaecologist may also check for that. Our guide to endometriosis stages explains how pelvic endometriosis is described.

Treatment

Treatment depends on your symptoms and whether your lung has collapsed.

• Hormonal treatment. The aim is to stop the tissue reacting to your cycle. Options include GnRH medicines, the combined pill, progestins and aromatase inhibitors. Our guide to endometriosis treatment options explains each type.
• Surgery. Keyhole surgery of the chest is the main treatment for thoracic endometriosis, often done with keyhole surgery of the pelvis at the same time.
• Surgery plus hormones. A procedure that helps the lung stay attached to the chest wall (pleurodesis), followed by hormonal treatment, appears to lower the chance it comes back.

Symptoms can return. Across the large review, 10.1% of people had symptoms again after treatment. Keep a record after treatment too, so you notice a change early.

What to track before your appointment

Thoracic endometriosis is found mainly from the pattern in your history, so clear notes help. For two or three cycles, write down:

• The day of your cycle when the pain or breathing problem starts and stops, counting day 1 as the first day of bleeding
• The side and place of the pain: chest, ribs, shoulder, shoulder blade, neck or upper belly
• How bad the pain is, from 0 to 10
• Breathing symptoms, such as shortness of breath or pain when you breathe in
• Any blood when you cough, and how much
• Pelvic symptoms in the same cycle, such as period pain or pain with sex

Endolog is a pain and symptom diary for endometriosis. You can log pain severity, where it hurts, bleeding, associated symptoms and flare notes on each day, and take a clear PDF summary to your doctor. If you prefer paper, print the free pain diary.

Frequently asked questions

Is chest pain during my period normal?

Chest pain during a period is usually from a common cause, such as breast pain, a chest strain, heartburn or anxiety. Sudden or severe chest pain is never something to wait out. Call your emergency number.

Why does my right shoulder hurt during my period?

Endometriosis on the diaphragm can cause pain felt in the shoulder or neck, and it is mostly on the right side. It is rare, so tell a doctor if it comes back with each period.

Can endometriosis make it hard to breathe?

Yes, rarely. Endometriosis in the chest may cause shortness of breath and coughing up blood. Sudden shortness of breath needs emergency help at once.

How is thoracic endometriosis diagnosed?

Doctors look at whether your symptoms line up with your period, then use a chest X-ray, CT or MRI. Keyhole surgery of the chest can confirm it.

This article is for general information. It is not medical advice and does not replace advice from your own doctor. If you think you have an emergency, call 911, 999 or your local emergency number.