How Pain Works: The Body’s Alarm System

Written By: Dr. Danielle L. Moreau PT, DPT on January 17, 2023

Pain is an essential part of being human and it helps us survive. Pain is a complex experience determined by many factors not just the presence or absence of injury.  

There are many examples which demonstrate that pain is more complicated than expected. For example, people can experience phantom limb pain after amputation, and research shows spine imaging such as X-rays do not correlate with how much pain a person has. Pelvic floor therapists frequently work with people who have pain, and sometimes this pain has lasted for months or even years. Many people in pain are dismissed when imaging or testing comes back negative. This can lead to frustration, hopelessness, and worse pain.

But there is hope!  Research shows learning how pain works not only improves function, but it decreases pain. This article is the first in a series discussing how pain works, starting with the body’s alarm system.  

What is Your Body’s Alarm System?
The body’s alarm system is made up of a network of more than 400 nerves - constantly sending messages between the brain and the rest of the body.  These nerves communicate information to the brain about temperature, stress, movement, immunity, and blood flow by sending electrical impulses.  Most of the time, the alarm system is idling at a consistent rate. This can be compared to how electricity is always running through your house, even when the light switches and your devices are off. 

When an injury occurs, the system fires off messages to the brain - telling it that there is danger, and there is a spike in electrical impulses. In other words, the light switch is turned on.  As a result, we experience pain helping to protect us from further harm or damage.  It also helps us to take care of the injury - perhaps a trip to the doctor is needed. As the injury heals over time, the electrical impulses return to their idling state and the light turns off.
What Happens If Your Body’s Alarm System is Extra Sensitive? 
There are times when the body’s alarm system does not return to an idling state after a pain experience or injury. Research shows this can happen with up to 1 in 4 people. This is often referred to as sensitization - meaning the alarm system has become extra-sensitive after an injury.  In this case, the tissues may have healed but the alarm has not calmed down all the way. Think about a fire alarm going off when there isn’t really any smoke or fire.  

There are many reasons this can happen, and sometimes it happens with no apparent explanation. When the body’s alarm system is extra-sensitive, it can be set off by normal daily tasks, resulting in ongoing pain and reduced function. And the more the alarm is set off, the easier it is to set off; essentially, your body gets good at feeling pain.  

Unfortunately, this change to the nervous system’s sensitivity is not shown on imaging, and so there is a discrepancy between the state of the tissues and a person’s pain. This can lead to a challenging road of failed treatments, an overwhelming number of doctor’s visits and testing, fear about the future, and loss of hobbies or work.  
Pelvic Floor Sensitization
A good example of sensitization is the pelvic floor. Pelvic pain can be associated with an extra-sensitive alarm system for many reasons including: 
  • Lack of social acceptance or support for pelvic floor issues.
  • Prevalence of sexual, medical, or other emotional trauma.
  • Fear of pain due to lack of anatomical knowledge.
  • The presence of chronic conditions such as endometriosis.  

When the alarm is extra-sensitive, the tissues around the pelvis become painful to touch or stretch, pressure changes, positions, or movements which can lead to bowel, bladder and/or sexual dysfunction.  

Treating Pelvic Floor Sensitization
A pelvic floor therapist’s role in treating pain and improving function is to guide people in learning how their extra sensitive alarm is being triggered and how to calm it down. The alarm system responds well to:
  • Movement
  • Aerobic exercise
  • Manual therapy
  • Breathing exercises
  • Graded exposure
  • Modalities such as ice, heat, or electrical stimulation
Treatment plans are highly individualized because the factors that cause the alarm system to stay sensitive are personal and vary from person to person. The treatment plan will also cover any lifestyle factors that contribute to the alarm staying sensitive, such as poor sleep, stress, and nutrition. This is also why a pelvic floor therapist may recommend other types of providers who understand the sensitive alarm to join the team. Above all, pelvic floor therapists know and understand that the pain is real and can be treated.  
Next: The Role of the Brain
Be on the lookout for more articles on how pain works. Next in the series, the role of the brain plays in how people experience pain.  

If you or someone you know is experiencing pelvic pain,  The Spaulding Outpatient Center for Pelvic Health at Care New England is designed to offer interdisciplinary treatments and services to address your specific pelvic health needs. 

•    Louw, A. (2013). Why do I hurt?: A patient book about the neuroscience of pain. Orthopedic Physical Therapy Products.
•    Louw, A., Hilton, S., & Vandyken, C. (2014). Why pelvic pain hurts: Neuroscience education for patients with pelvic pain. International Spine and Pain Institute. 

Disclaimer: While I am a doctor, I am not your doctor.  The content in this blog is for informational and educational purposes only and should not serve as medical advice, consultation, or diagnosis.  If you have a medical concern, please consult your healthcare provider, or seek immediate medical treatment.