Endometriosis can cause shoulder pain. It’s one of the most frequently dismissed and misunderstood symptoms of the disease, but the connection is very real. If you experience shoulder pain that seems to appear or worsen with your period, it’s not a coincidence—it’s a classic sign of thoracic endometriosis.
At Endometriosis Surgical Specialists International (ESSI), we specialize in diagnosing and treating all forms of endometriosis, no matter how rare. Unraveling symptoms like cyclical shoulder pain is key to our comprehensive, patient-centric approach.
How a Pelvic Disease Causes Shoulder Pain
The link between your pelvis and your shoulder seems confusing until you understand the role of your diaphragm and the nerve that controls it.
The primary cause of endometriosis-related shoulder pain is the presence of endometrial lesions on the diaphragm, the dome-shaped muscle that separates your chest from your abdomen and helps you breathe. This is known as diaphragmatic endometriosis.
The crucial link is a nerve called the phrenic nerve. This nerve originates in your neck (near vertebrae C3-C5) and travels down through your chest to control the diaphragm’s movement.
When endometriosis on the diaphragm becomes inflamed during your period, it irritates the phrenic nerve. The nerve sends a pain signal back up to the brain, but because of its origin point in the neck, your brain interprets the pain as coming from your shoulder. This phenomenon is called “referred pain.” It’s the same reason a heart attack can cause arm pain.
Frequently Asked Questions About Endometriosis Shoulder Pain
Q1: What does this pain feel like?
The pain is often described as a sharp, stabbing, or deep, severe ache. You might feel it at the top of your shoulder, deep in your shoulder blade, or in your upper arm. It can be accompanied by shortness of breath or a sharp pain when you take a deep breath.
Q2: Why is it almost always the right shoulder?
For reasons that aren’t fully understood, endometriosis lesions are far more likely to implant on the right side of the diaphragm. Therefore, the irritation to the phrenic nerve is on the right side, and the referred pain is felt in the right shoulder. Left-sided shoulder pain is possible but much less common.
Q3: What should I do if I have cyclical shoulder pain?
The most important thing you can do is track your symptoms and report the cyclical pattern to your doctor. Standard imaging of your shoulder, like an X-ray or ultrasound, will be normal. The key is to tell your doctor, “My shoulder hurts every month with my period.” This information is the biggest clue that points toward a diaphragmatic cause and warrants an evaluation by an endometriosis specialist.
Expert Treatment for a Complex Condition
Diagnosing and treating diaphragmatic endometriosis requires a high level of expertise. It often involves advanced imaging, like a specialized MRI, to visualize the diaphragm.
The definitive treatment is meticulous surgical excision by a surgeon skilled in operating in the upper abdomen. Safely removing the lesions from the delicate diaphragm muscle is the only way to stop the irritation of the phrenic nerve and resolve the referred shoulder pain for good. Your symptoms are real, and a solution exists.
