The Sources of Pain

The Source Makes a Difference

Why do we even have pain signals?

You'd think the whole world would be better if we just didn't have pain at all. But it's simply not that easy. Pain is actually really important. The whole purpose of pain is to alert your brain to possible tissue damage, so you move your hand off a hot stove. People who have spinal cord injuries sometimes get a cut where they can't feel it. The cut then becomes infected, and the person doesn't know until they're really sick with high fevers and possibly sepsis. It's important for our bodies to be able to feel pain to keep us safe.

Where do pain signals come from?

Pain signals related to tissue damage start with activation of something called nociceptors. These are sensory neurons all around your body that fire when there's possible tissue damage. They are easier to activate when there's inflammation and immune system activation hanging around. These two things are what help your body heal wounds and prevent infections. It makes sense that when your body is trying to fight an infection, you might want to know about it. 

 When your body is sending pain signals related to possible damage, the signals can come in different kinds of flavors:organ pain and non-organ pain. 

Pain coming from internal organs

Organ pain comes from internal organs such as your stomach, gallbladder, uterus, ovaries, intestines, and bladder.  

Pain signals from your organs mostly come from the organ being stretched (such as your stomach when you eat too much), lack of blood flow (such as your foot “going to sleep” when you sit on it), and inflammation (caused by illness or injury).

Acute pain* from an organ can be caused by appendicitis, a hot gallbladder or a heart attack. It may be accompanied by symptoms such a tightness or squeezing fullness, being pale, sweaty, or feeling a sense of impending doom. Heart attack symptoms also may include pain in the left arm, shoulder, neck, and jawline. Acute pelvic organ pain is most often felt with bladder infections or period cramps. 

Chronic pain** from an organ tends to be more like a dull ache, discomfort or nausea that won’t go away. The pain can fluctuate. When it is bad, you can have nausea and sweating. When the pain lessens, you’ll experience a more general discomfort. Perhaps you’ll feel a constant need to urinate or empty your bowels. These sensations are common.

Pain coming from other places.

Pain from skin, muscle, bones, joints, and ligaments is considered non-organ pain. These are usually a little easier for your brain to figure out. The neurons in these locations will fire with almost any unpleasant sensation; stretch, heat, cutting, inflammation etc...

In your pelvis, though, the pain signals get mixed up with the organs, making it especially hard for your brain to figure things out.

The pelvis is a tight area, with lots of stuff in it, including your bladder, uterus, tubes, ovaries, bowel, muscles, nerves, and fascial tissue. The body has to transmit information from all these things to the brain for processing. Because it's such a tight area, there's only a few spots in the spinal cord that are available to transmit ALL of this information. Once the information gets to the spine, the pain signals all get thrown in together. What your brain reads is "there's pain somewhere in my pelvis". Every body feels that different. Some people feel it as bladder pain or bowel pain, some feel it as ovary pain.

What is pelvic and intimate pain, and what can be done about it?

Pain specialists define pelvic pain as anything that hurts between your belly button and mid thighs, front and back. (See What’s in the Pelvis?). Intimate pain is anything that hurts in your genital region, including pain with sexual intercourse.

You may have been told at one time that your pain is “all in your head,” or you’re “blowing things out of proportion.” But rest assured, chronic pelvic and sexual pain are medical problems.

Seeking help from a pelvic pain specialist is the best approach to help diagnosis and manage pelvic pain. S/he can teach you how to get your brain and body to stop making your pain worse than it needs to be.

* Acute pain is defined as a one-time or brief event

**Chronic pain is defined as lasting from a few weeks to more than six months

References:

1. Aredo J, Heyrana K, Karp B, Shah J, Stratton P. Relating chronic pelvic pain and endometriosis to signs of sensitization and myofascial pain and dysfunction. Seminars in Reproductive Medicine. 2017;35(1):88-97.
2. Huang L, Kutch JJ, Ellingson BM, Martucci KT, Harris RE, Clauw DJ, Mackey S, Mayer EA, Schaeffer AJ, Apkarian AV, Farmer MA, MAPP. Brain white matter changes associated with urological chronic pelvic pain syndrome: multisite neuroimaging from a MAPP case-control study. Pain. 2016;157:2782-2791.

How Your Body and Brain Process Pain

How Your Body and Brain Process Pain

Pain is processed differently, depending on its source.

When pain is generated in your body, it is transmitted as a signal to the spinal cord, past several gateways, and then to the brain where it is finally processed. Once the brain decides the signal warrants a response, and what kind of response, it sends a signal back down to the body for a reaction.

Here’s a simple diagram:



Copyrighted 2018 When It Hurts Down There

One time, brief pain

When the pain is a one-time or brief event (also called “acute”), the signals follow a path like the one pictured here. For instance, if you burn your left hand with a curling iron, the cell damage in your skin is the instigator of the pain signal. The signal goes to your spinal cord, which sends the signal up to your brain.

If your lower midbrain decides the signal is important, the signal gets passed on to the midbrain. These gateways decide how bad the pain is and relies on the upper brain to confirm: it’s your left hand; the pain is moderately intense; and that it’s a burn and not a cut. The brain then sends a signal to your right hand to move the curling iron away from the skin and to put your left hand under cold water. This all happens in a split second.

Chronic, lasting pain

With chronic (constant) pain, weird things happen with the pain signals in the body. When the same nerves in the body have to fire over and over again, they’ll yell for help by releasing nerve-recruiting chemicals.

When you get the experience of pain over and over again, the brain can’t tell if it’s dangerous, and the nerves in the brain can start overreacting.

For example, the body may think there’s damage, such as inflammation, immune system activation, or an abnormal nerve signal. So the pain-processing nerves in the brain think that they too need more help. They start recruiting their brain neighbors to help process the pain, and make more connections and branches. This “neighboring help” may partly be driven by inflammation and stress that can result in high levels of inflammation chemicals and stress hormones. All this activity from the constant pain can make the brain more sensitive to pain.

With pelvic pain, the brain doesn’t know exactly where the pain signals are coming from. When you have chronic pain in your pelvis, your body may not have to send a signal to the brain to get a reaction. It can just start reacting on its own! And the brain can also get mixed signals from the “neighboring help” and link things like your daily bodily functions, touch, and movement to the pain.

Think of the pain signal in your body acting like a fire alarm.

Normally a fire alarm goes off only if there's smoke or a fire. You wouldn’t expect the alarm to sound when you simply light a match or turn on the stove. Normally you wouldn’t expect pain because of average bodily functions, such as having a bowel movement or coughing, or when you have sex. But when your body and brain get overly sensitized to the pain, bodily functions, normal touch, and movement will now cause pain too.

As a result, your “alarm” will go off randomly, even when there’s nothing happening!

Seeking help from a pelvic pain specialist is the best approach to help diagnosis and manage pelvic pain. And given the complexity of the pelvic area (See What’s in the Pelvis?), pain is often in more than one site. Your specialist can untangle where your pain is coming from and recommend a course of treatment.

References:



Hampson JP, Reed BD, Clauw DJ, Bhavsar R, Gracely RH, Haefner HK, Harris, RE. Augmented central pain processing in vulvodynia. J Pain. 2013;14(6):579-589.

Janicki T. Chronic pelvic pain as a form of complex regional pain syndrome. Clinical Obstetrics and Gynecology. 2003;46(4):797-803.

Mercier C, Léonard G. Interactions between pain and the motor cortex: Insights from research on phantom limb pain and complex regional pain syndrome. Physiother Can. 2011;63(3):305-314.

Kim W, Kim SK. Neural circuitry remodeling and structural plasticity in the cortex during chronic pain. Korean J Physiol Pharmacol. 2016;20(1):1-8.

Aredo J, Heyrana K, Karp B, Shah J, Stratton P. Relating chronic pelvic pain and endometriosis to signs of sensitization and myofascial pain and dysfunction. Seminars in Reproductive Medicine. 2017;35(1):88-97.

Lee Y, Park K. Irritable bowel syndrome: Emerging paradigm in pathophysiology. World J Gastroenterology. 2014;20(10):2456-2469.

Schrepf A, O’Donnell MA, Luo Y, Bradley CS, Kreder KJ, Lutgendorf S, MAPP Network. Inflammation and inflammatory control in interstitial cystitis/bladder pain syndrome: associations with painful symptoms. Pain. 2014;155(9):1755-1761.

what's in the Pelvis

What’s in the Pelvis?

Understanding the complexity of the pelvis goes a long way in understanding why it may be difficult to pinpoint and treat the exact source of your pain and discomfort.

The pelvis is a tight area with many organs and structures. It includes your bladder, uterus, Fallopian tubes, ovaries, bowels, muscles, nerves, skin, and more!



Copyrighted 2018 When It Hurts Down There



The body transmits information from all these parts and places to the spinal cord, which sends the signal to the brain for processing. The problem lies in the fact there are only a few spots in the spinal cord available to transmit all of this information.

From the picture you can see in the picture how complex and interwoven the parts of the pelvis are, and how a pain signal might get confused on its way to the spinal column and brain.

As a result, what your brain receives is "there's pain somewhere in my pelvis." Because the brain is not sure of the origin of the pain or the severity, it has to guess. And on top of that, the brain can become so confused that the organ and skin pain signals get mixed up. So, while it may be that your bladder needs attention, you feel it in the muscles and skin of your buttocks.

Without knowing the source of the pain, getting a firm diagnosis is a challenge. Which is why a pelvic pain specialist can help. S/he can untangle where your pain is coming from, which is often more than one site, and develop a course of treatment.

1. Aredo J, Heyrana K, Karp B, Shah J, Stratton P. Relating chronic pelvic pain and endometriosis to signs of sensitization and myofascial pain and dysfunction. Seminars in Reproductive Medicine. 2017;35(1):88-97.