How common is the symptom Shoulder pain among people with endometriosis?
61,50% of people with endometriosis reported Shoulder pain as a symptom of endometriosis in our survey.
How common is the symptom Shoulder pain among people with endometriosis compared to the non-affected group?
12,02% of people with endometriosis suffer from the symptom Shoulder pain very strong compared to a prevalence of 4,40% among non-affected individuals.
The following table shows the symptom Shoulder pain in people with endometriosis compared to non-affected individuals. The scale ranges from 1 (not at all) to 5 (very strong).
| Symptom severity | Endometriosis | Non-affected | Comparison |
|---|---|---|---|
| not at all | 38,50% | 47,17% | -8,67% |
| slightly | 14,68% | 18,87% | -4,19% |
| moderate | 18,03% | 19,50% | -1,46% |
| strong | 16,76% | 10,06% | 6,70% |
| very strong | 12,02% | 4,40% | 7,62% |
Based on the datasets, we calculated the Kendall correlation. The following symptoms could be related to Shoulder pain.
| Symptom name | Correlation |
|---|---|
| Joint pain | moderate correlation (36,00%) |
| Limb pain | moderate correlation (33,00%) |
| Shortness of breath | moderate correlation (31,00%) |
| Back pain | moderate correlation (31,00%) |
| Numbness in hands | moderate correlation (30,00%) |
| Numbness in legs | weak correlation (28,00%) |
| Leg pain | weak correlation (25,00%) |
| Kidney pain | weak correlation (25,00%) |
| Exhaustion / Fatigue | weak correlation (23,00%) |
| Taste changes (e.g. iron taste) | weak correlation (23,00%) |
| Chest pain | weak correlation (23,00%) |
| Abdominal pain outside the lower abdomen | weak correlation (23,00%) |
| Heartburn | weak correlation (22,00%) |
| Belching | weak correlation (22,00%) |
| Headaches / Migraine | weak correlation (21,00%) |
| Dizziness | weak correlation (21,00%) |
Shoulder pain is usually attributed to muscle tension, injuries to muscles or joints, or degenerative changes. However, shoulder pain can also be a symptom of endometriosis. In women with endometriosis, tissue similar to the uterine lining is found in other parts of the body. These misplaced endometriotic lesions are usually located in the pelvis, but they can also occur throughout the abdominal cavity, including on the diaphragm. The diaphragm is a dome-shaped muscle that lies between the abdominal cavity and the lungs. Because the diaphragm and the shoulder share the same nerve pathways, injury or irritation of the diaphragm can be perceived as shoulder pain.
This is what happens in diaphragmatic endometriosis: The misplaced cells, like the endometrium in the uterus, respond to your hormonal cycle. This means that the mucosal deposits first grow and then bleed. This leads to space-occupying lesions, inflammation, and, in some cases, scarring. The result is pain perceived in the chest, upper abdomen, and also in the shoulder and arm. Because endometriotic lesions most often occur on the right side of the diaphragm, endometriosis-related shoulder pain is usually right-sided. As a rule, shoulder pain occurs on the same side as the diaphragmatic endometriotic lesion. Shoulder pain from diaphragmatic endometriosis usually first appears in temporal relation to your period. However, the pain can become chronic, especially if adhesions or scarring have developed.
Women who have diaphragmatic endometriosis usually also have endometriotic lesions in the pelvis. If pelvic endometriosis is asymptomatic, it often takes a very long time for shoulder pain to be recognized as a symptom of endometriosis. If there is suspicion that shoulder pain is caused by an endometriotic lesion on the diaphragm, the work-up can include MRI and laparoscopy (minimally invasive surgery) with biopsy (tissue sampling).