Chronic pain conditions often occur together in the same person, which means that they may have similar underlying causes.
There is substantial evidence that endometriosis is estrogen-dependent and related to immune dysfunction and chronic inflammation (1). Although often hormonal and inflammatory in nature, no two people are identical in their causes, symptoms or experience of their symptoms. For example, two people with confirmed severe endometriosis can present very differently. One person may have pain on most days of the month and suffer from many different types of pain, depression, migraines, bladder and/or bowel troubles, while the other person may have bad period pain but is otherwise completely well.
Why the disconnect between disease stage, progression, and symptoms?
No one knows exactly how endometriosis causes pain, but chronic pain conditions often occur together in the same person. This suggests that chronic overlapping pain conditions may have common underlying disease mechanisms.
If you are suffering from persistent pain, you may recall when your only problem was period pain or lower back pain. Then, something happened. Maybe it was a really bad period, a stressful situation, a traumatic injury, a bad relationship, a new job, the birth of your baby, chronic stress, or for no reason at all. Now, everything feels more sensitive or more painful. New symptoms may have started as well, like a swollen belly, brain fog, or debilitating fatigue.
This is called central sensitization and is thought to facilitate the development of chronic pain. Basically, your nervous system received a threatening signal and dialed up the sensitivity meter so it could pay close attention. The brain reads the signal, perceives the need for a protective response, and reacts in a way that creates pain.
The function of acute pain is to protect us from danger. But what happens when there is no longer a threat? In some cases, instead of settling down once the original injury has healed, the nerves change their structure.
Central sensitivity is associated with long-term changes in pain pathway structures. This is known as neuroplasticity. It can affect the way a nerve sends signals and the way the nervous system perceives those signals. Basically, nerves become irritated, injured or sensitized, and change their structure. As a result, the way the nervous system perceives painful impulses also changes. The brain now misinterprets normal, non-harmful signals from the body as dangerous. There may also be increased sensitivity to a normally painless stimulus (touch, pressure, pinprick, cold, and heat), and wind-up pain (pain felt over a larger area than usual when it is severe compared to when it is mild).
Can endometriosis cause central sensitization?
Yes, through the formation of new blood vessels and nerves as the lesions grow. And because endometriosis is an inflammatory condition. Inflammation in the body can sensitize the nervous system (2).
This can become a vicious cycle. The nervous system has become highly vigilant and sensitized. Normal, non-harmful signals from the body cause pain. New, painful conditions develop in many different systems of the body. Negative emotions, stress, illness perceptions, pain cognitions, and pain behavior contribute to (or even trigger) persistent pain. All of this new information feeds back to the brain, keeping the nervous system from calming down, and reinforcing the process.
Even in the absence of tissue injury or inflammation, people with central sensitization can feel pain. Neuroplastic changes increase pain transmission all over. That is why you may develop other pains. Your pain is real. It’s in your brain, but it is not in your head.
If you look at the figure above, you can see that “inputs” or incoming signals that your brain receives (from nerve endings) are interpreted in the context of other information from many different brain areas, such as those related to sensations, memories, emotions, thoughts, perceptions, fears, goals, etc.
There is no specific pain center in the brain. Pain emerges from the complex interactions of many different parts. The brain (aka the neuromatrix in the figure above) takes in all of the available information and then decides if pain is needed for protection.
Pain is a protective response, like an alarm system. Responses or “outputs” may include fatigue, muscle pain, joint pain, sleep disturbances, mood alterations, difficulty concentrating and remembering things, stomach pain, and bloating. Even stress is a protective response that involves changes to the immune system and endocrine system, which help mobilize resources to deal with the threat (real or perceived). These “outputs” become new “inputs” into the system, and the process repeats in a slightly altered form. This is an adaptive response.
Adaptation: a body part or feature or a behavior that helps a living thing survive and function better in its environment.
Perception is a powerful tool
Pain can be activated by the unconscious perception of threat, whether or not a real threat exists. If you perceive yourself to be weak, incapable, under attack, broken, fragile, damaged, vulnerable to threats, etc., then your brain will respond in a way necessary for protection. The nervous system is always at work, reading and interpreting evidence about our environment in the context of our past and present state.
How will you break out of your pain cycle?
No one model exists for understanding all experiences of persistent pain. When looking at the bigger picture of pain, we can now appreciate that there are many factors that work together to cause pain and affect the body as a whole. A good first step may be finding a supportive healthcare provider who will help you understand the connections between your symptoms and contributing factors, such as those related to chronic stress. Most of us are aware of emotional stress or have experienced it to some degree, but what about other sources of chronic stress? Nutritional deficiencies, inadequate sleep, emotional stress, too much exercise, physical illness, environmental toxins, poor blood sugar regulation, etc. drive body inflammation and brain inflammation, which sets the stage for hypersensitivity to pain.
Sensitized nervous systems can slowly shift back to a normal level of pain sensitivity, especially when they are supported with rest, recovery, sleep, nutrition, stress management, positive mindset, support, and healthy forms of challenge (ie good stressors like slow and novel movements). Think of this approach as a reset to baseline sensitivity levels.
A multidisciplinary or integrative approach is considered the “gold standard” or best practice for persistent pain.
There is no single treatment that adequately addresses every symptom in every person; hence the need for individualized care and a multidisciplinary holistic approach. All involved healthcare providers must take the time to explore and fully understand the constellation of symptoms that you experience as a unique individual.
In addition to pain management, what is/are your desired outcome/s? Clarity of mind? Better sleep? Increased energy levels?
There is strong evidence that multi-component approaches, typical of a holistic naturopathic or functional medicine approach, further improve health outcomes. Inquire about the modalities and perspectives of different practitioners and their treatment approaches. What resonates with you?
With or without the use of pharmaceutical interventions, it is important to find an approach or combination of approaches that suits you and helps your pain. Lifestyle changes, mind-body practices, pain education, targeted dietary support, herbal medicine, and/or nutritional supplements can help break your pain cycle and improve the quality of your life.
- Romm Aviva Jill. (2018). Botanical Medicine for Women’s Health, 2nd Ed.
- Evans, S. & Bush, D. Endometriosis and Pelvic Pain. 3rd Ed. 2016.