Understanding Endometriosis Pain: Types, Evaluation, and Treatment

Introduction

Endometriosis is a chronic gynecological condition where tissue similar to the lining inside the uterus grows outside it, causing pain and potentially leading to fertility issues. The types of pain varies quite a bit because of different organ involvement, among other factors. 

Common Endometriosis Pain Symptoms

Here are some of the more common types of pain that endometriosis can manifest: 

1. Dysmenorrhea: Severe menstrual cramps that can start before and extend beyond the menstrual period.
2. Non-menstrual Pelvic & Abdominal Pain: Chronic pain in the lower abdomen and pelvis, unrelated to menstruation, most often related to intestinal bloating (endo-belly). 
3. Dyspareunia: Pain during or after sexual intercourse.
4. Dyschezia: Painful bowel movements.
5. Dysuria: Painful urination, often exacerbated during menstruation.

There can be many other types of pain which vary depending on what organ might be involved. This makes the cause very difficult to diagnose correctly, and endo is often not the first condition that comes to mind. However, since it can cause many forms of pain, it must always be considered. More unusual examples include leg pain where the sciatic or femoral nerves may be involved or compressed, or pain with breathing due to diaphragmatic or even pleural (peritoneum within the chest cavity) and lung involvement. 

Evaluation of Endometriosis Pain

Evaluating endometriosis pain effectively is crucial for proper diagnosis and treatment planning. The Visual Analog Scale (VAS) and the Numerical Rating Scale (NRS) are recommended for their balance of strong and weak points compared to other scales (Bourdel et al., 2021). Additionally, the Endometriosis Pain Daily Diary (EPDD), a patient-reported outcome (PRO) instrument, has been developed to assess endometriosis-related pain and its impact on patients’ lives (van Nooten et al., 2018).  There are other outcomes assessment tools and it is important to use at least one of them so you can document whether is not something is actually helping or not. 

Pain Triggers in Endometriosis: Mechanisms and Treatments

So, how does endo actually cause pain?  It is due to a combination of overlapping nociceptive (nerve receptor activation), inflammatory, and neuropathic pain.  At the end of the day, pain is pain, but this opens up a number of different treatment options that can be used together to improve quality of life. Trying to address only one or two of these causes may not get you the best results.  

First, here are the most common triggers and treatment options. 

Peritoneal Prostaglandin Stimulation

Peritoneal prostaglandins are inflammatory mediators that play a significant role in the pain associated with endometriosis. They are produced by endometriosis lesions and contribute to inflammation and pain by sensitizing nerve endings in the pelvic region peritoneum.

Best Treatments:

1. NSAIDs: Nonsteroidal anti-inflammatory drugs, such as ibuprofen and naproxen, are effective in reducing inflammation and prostaglandin production, thereby alleviating pain.  This does not actually treat the endometriosis. But knowing which type of NSAID is best for you is helpful for decisions.  
2. Hormonal Therapies: Medications like oral contraceptives, progestins, and GnRH agonists or antagonists can help reduce the menstrual cycle and thus decrease prostaglandin production. Significant risk vs. benefit considerations exist and requires expert input to get to the best choices that optimize overall outcomes.  This approach, just like NSAID treatment, does not treat the endometriosis well due to relative progesterone resistance, among other factors. 
3. Surgical Interventions:
   1. Laparoscopic and Robotic Surgery: Minimally invasive procedures provide two benefits.  First of all, a biopsy, which is most often obtained by surgery, is the only way to be certain that endometriosis is at least part of the reason for pain. Second, it has the potential for relatively immediate relief of pain because it removes the lesions which directly affect nociceptive stimulus and removes the chronic inflammation stimulus which affects the pelvic floor.  Surgery not only improves symptoms but is also a cornerstone therapy for endometriosis. 
   2. Hysterectomy: In severe cases, removing the uterus may be considered as a last resort to alleviate pain.  In some cases, for example, the uterus is essentially encased in endometriosis and fibrosis.  But otherwise, it is not necessary and is obviously inconsistent with child-bearing.  However, considerations related to possible coexisting adenomyosis may impact decisions about pain relief vs fertility.  

Pelvic Floor Stimulation

Pelvic floor dysfunction is a common issue in women with endometriosis, often resulting from chronic pain and muscle spasms. This can lead to additional pain and discomfort, especially during activities like intercourse, bowel movements, or urination.

Best Treatments:

1. Pelvic Floor Physical Therapy: Specialized physical therapy focusing on the pelvic floor can help reduce muscle spasms, improve muscle function, and alleviate pain.  This may include external and internal manipulation as well as transcutaneous electrical nerve stimulation (TENS). 
2. Biofeedback Therapy: This technique uses electronic monitoring to help patients gain awareness and control over their pelvic floor muscles.
3. Trigger Point Injections: In some cases, injections of anesthetics or steroids directly into the painful areas of the pelvic floor muscles can provide relief.

Central Nervous System Sensitization

Central nervous system (CNS) sensitization refers to the heightened sensitivity of the CNS to pain signals, often seen in chronic pain conditions, including endometriosis. This can result in exaggerated pain responses to stimuli that would not normally be painful.

Best Treatments:

1. Cognitive-Behavioral Therapy (CBT): This psychological treatment helps patients manage pain by changing negative thought patterns and behaviors associated with chronic pain.
2. Transcranial Direct Current Stimulation (tDCS): This non-invasive brain stimulation technique has been shown to decrease pain perception in patients with chronic pelvic pain and endometriosis (Mechsner et al., 2023).
3. Pharmacological Treatments: Medications such as anticonvulsants (e.g., gabapentin, pregabalin) and antidepressants (e.g., amitriptyline) can help reduce neuropathic pain by modulating the pain pathways in the CNS.
4. Interdisciplinary Approach: Combining various treatments, including medication, physical therapy, and psychological support, can be effective in managing chronic pain due to CNS sensitization (Allaire et al., 2017).

General Holistic and Integrative Approaches

1. Dietary Changes:
   • Anti-inflammatory Diets: Foods rich in fruits, vegetables, lean proteins, and omega-3 fatty acids, can help reduce inflammation and pain. You should especially consider brassica veggies, leafy greens, berries, fatty fish like salmon, and nuts.
   • Avoiding Certain Foods: Reducing intake of processed foods, caffeine, alcohol, and high-fat meats may help alleviate symptoms.
2. Acupuncture and Herbal Medicine:
   • Acupuncture: This Traditional Chinese medicine technique involves inserting thin needles into specific points on the body to relieve pain. Whether you believe it is related to meridians or nerve pathways, we know it is effective in many people. 
   • Herbal Treatments: Herbs like turmeric (curcumin), ginger, and chamomile have anti-inflammatory properties and can be used as supplements or in teas.
3. Endocannabinoids: The “internal” endocannabinoid system (ECS) has emerged as a significant pharmacological target for managing endometriosis-related pain (Bouaziz et al., 2017).
4. Cannabis: “External” use of CBD interfaces with the internal system because the target receptors are shared.  In addition, under expert guidance and where legal, THC may also help.  However, the latter has psychoactive effects which may not be desired.  
5. Mind-Body Techniques:
   • Yoga: Incorporates physical postures, breathing exercises, and meditation to reduce stress and improve flexibility and pain management.
   • Meditation and Mindfulness: Techniques that focus on reducing stress and improving emotional well-being, can indirectly help manage chronic pain.
   • Cognitive-Behavioral Therapy (CBT): This specific psychological treatment helps patients manage pain by changing negative thought patterns and behaviors.
6. Supplements and Natural Remedies:
   • Omega-3 Fatty Acids: Found in fish oil supplements, these can help reduce inflammation.
   • Vitamin D: Supplementing with vitamin D can improve immune function and potentially reduce endometriosis symptoms.
   • Magnesium: This mineral helps relax muscles and reduces cramping and pain.
7. Lifestyle Modifications:
   • Regular Exercise: Moderate physical activity, such as walking, swimming, or yoga, can help reduce pain by releasing endorphins, the body’s natural painkillers.
   • Stress Management: Techniques like deep breathing, progressive muscle relaxation, and guided imagery can help manage stress, which can exacerbate pain.

Adenomyosis and Pain Mechanisms

Adenomyosis is a condition, highly related to endometriosis, in which the inner lining of the uterus (endometrium) breaks through or is transported into the muscle wall of the uterus (myometrium). This can cause significant pain and heavy menstrual bleeding. The mechanisms through which adenomyosis causes pain overlap with endo but have some additional separate issues. 

1. Increased Nerve Fiber Density: Studies have shown that increased nerve fiber density in adenomyotic tissue is correlated with more severe pain. This suggests that the proliferation of nerve fibers within the uterine muscle layer is a significant factor in the pain experienced by patients with adenomyosis (Lertvikool et al., 2014).
2. Inflammation and Prostaglandin Release: Adenomyosis leads to chronic inflammation within the uterine muscle, resulting in increased levels of inflammatory mediators like prostaglandins. These mediators cause painful uterine contractions and contribute to the severe pelvic pain associated with the condition (MacGregor et al., 2023).
3. Myometrial Invasion: Adenomyotic lesions invade the myometrium through processes such as epithelial-mesenchymal transition, which can cause pain through abnormal uterine bleeding and severe pelvic discomfort (Tan et al., 2019).  There may also be transportation via lymphatics, but the end result is the same. 
4. Abnormal Uterine Bleeding: The disruption of normal uterine architecture leads to abnormal bleeding patterns, which can exacerbate pain and contribute to dysmenorrhea (painful periods) (López et al., 2020).

Best Treatments for Adenomyosis-Associated Pain

To address the pain associated with adenomyosis, several treatment strategies can be employed:

1. Hormonal Treatments:
   • Gonadotropin-Releasing Hormone (GnRH) Agonists and Antagonists: These drugs reduce estrogen levels, which can shrink adenomyotic lesions and reduce pain.
   • Progestins: Hormonal medications like Dienogest (DNG) can effectively manage pain by suppressing the growth of adenomyotic tissue, though they may be associated with side effects such as abnormal uterine bleeding (Kobayashi, 2023). There is some developing data that natural compounded progesterone works better than synthetic progestins. 
   • Levonorgestrel-Releasing Intrauterine System (LNG-IUS): This device releases a small amount of progestin directly into the uterus, reducing pain and bleeding by suppressing the endometrial tissue growth (Choi et al., 2010).
2. Non-Hormonal Treatments:
   • NSAIDs: Nonsteroidal anti-inflammatory drugs can reduce pain by decreasing inflammation and prostaglandin production.
   • Acupuncture and Herbal Remedies: Traditional Chinese Medicine treatments such as acupuncture and herbal formulas like Shaoyao-Gancao Decoction (SGD) have shown promise in reducing pain by targeting inflammation and muscle relaxation (Guan et al., 2014).
3. Surgical Interventions:
   • Laparoscopic and Robotic Surgery: Minimally invasive procedures can remove some adenomyotic tissue which may lead to some relief but may impact fertility if the uterine cavity is entered.  Also, since adenomyomas are now considered to be part of diffuse adenomyosis, removing all of it is highly problematic if not impossible.  
   • Hysterectomy: In severe cases, removing the uterus may be considered as a last resort to alleviate pain and improve the quality of life for patients who do not respond to other treatments.  Hysterectomy is not always required to effectively treat endometriosis pain.  However, if adenomyosis is also present, which is hard to accurately diagnose with imaging or examination, consideration should be given for a hysterectomy if childbearing is complete. 

Challenges and Future Directions

Communication with your doctor(s) about endometriosis pain can be challenging due to the subjective nature of pain and the complexity of the condition. Improved language and tools have been suggested to enhance patient-practitioner communication (Bullo & Weckesser, 2021). Additionally, ongoing research into genetic correlations and new treatment targets, such as the P2X3 receptor and brain-derived neurotrophic factor (BDNF), is crucial for developing more effective treatments (Ding et al., 2018).  The good news?  There is a lot of research going on regarding chronic pain and it’s not limited to endometriosis.  

Conclusion

Endometriosis pain is a multifactorial issue requiring a comprehensive evaluation and a multifaceted treatment approach. Combining medical, surgical, and holistic treatments can provide the most effective relief and improve the quality of life. For further reading and detailed studies, please refer to the linked references in this article. 

What type of endo pain do you have? And how would you describe it? If you want to find an experienced endometriosis specialist or a different kind of endo provider near you, you can do so on our platform, iCareBetter. 

References and More Information: 

• Bourdel et al., 2021
• van Nooten et al., 2018
• Wang et al., 2019
• Bouaziz et al., 2017
• Bullo & Weckesser, 2021
• Ding et al., 2018

Updated Post: July 29, 2024