What are “Functional Pain Disorders”?

Brought to you by CHYP’s Parenting Blog

November 22, 2021

By: Lonnie Zeltzer, MD

We have all been indoctrinated in the “Biomedical Model” of disease and symptoms. Something hurts, so find the cause and fix it.

Sometimes this task is easy. Your child falls and breaks an arm. You go to the ER and the x-ray shows the fracture and the arm is put into a cast. That makes sense — broken bones hurt.

Sometimes, though, your child complains of pain inside the body:  head, chest, belly, or arm/leg with no outward swelling or redness.

Maybe this is not complicated either. There are classic signs of appendicitis on the physical exam, in addition to a high white blood cell count, so your child goes to surgery to have the offending appendix removed. The original severe pain is gone and soon the post-operative pain resolves.

When Diagnosis is Not Straightforward

However, sometimes diagnosis (and treatment) is not so easy or straightforward. Then what? The primary care doctor can’t figure out the cause of the pain, so your child is sent to a pediatric subspecialist depending upon the location of the pain: gastroenterologist, orthopedist, neurologist, etc. But what if the specialist does routine – and increasingly invasive – tests and can’t find a cause?

The doctor may refer you to a different specialist – a rheumatologist or sports medicine doctor, for example. Or you may choose to take your child to a second doctor with the same specialty, and that doctor may repeat the same tests and/or conduct new tests.

After your child has seen different specialists, been given different medications, and worked with a physical therapist, what if the pain is still there? By now, between the pain, tests, doctors and PT visits, your child has missed a lot of school and is becoming anxious about how to catch up.

Maybe you start searching the Internet and find websites for doctors and other clinicians who offer treatments that have “cured” people with presumably the same problem your child has. You might start spending lots of money for these treatments, since most or all are not covered by insurance.

You’ve taken time off work, and are beginning to feel helpless and frustrated. Your child may be tearful and spending most of the time in bed, feeling more isolated, lonely, and disillusioned with doctors. Maybe, by this time, your child is both anxious and depressed — perhaps even suicidal. What now?

The Biomedical vs. Biopsychosocial Model of Disease

The problem goes back to the old biomedical model of disease that involves “ruling out diseases until you find the cause of the pain.” It is a narrow deductive process based on the location of pain and ruling out other likely causes.

While the biomedical model searches for “the cause” of the pain, the biopsychosocial model uses an inductive process where you gather multiple pieces of information to form a theory.

The biopsychosocial model provides a pathway to learning how the pain might have started — but also what changed the pain along the way, what contributed to it, what caused the pain to spread to other areas, what other problems the pain has created (school absences, sleep problems, eating problems, fatigue, sadness, anger, etc.) — and how all of these factors have contributed to the pain. Soon we are looking at a whole system that needs to be untangled to be addressed.

Chronic Pain = “Functional Pain”

Precious time can be wasted while searching for the cause of the pain, during which new problems can arise. Lying in bed and not exercising causes myofascial (muscle) pain and weakness. Now arms, legs, back, neck — even head muscles — begin to hurt. The less we move our bodies, the more tired we feel and fatigue sets in. Lack of exercise during the day makes it hard to sleep well at night or have an appetite during the day.

Less energy to engage in schoolwork or social activities can lead to feelings of loneliness, isolation, and depression. Pain flares can lead to anxiety and panic, with a focus on worrying about the next pain flare. “Learned helplessness” can occur when your child no longer believes anyone can help him/her and may believe that the doctors think he/she is crazy or making up the pain to get attention or get out of school.

We call these chronic pains “functional pain” because they disrupt function and are related to the effective function of the pain signaling system. Researchers can see changes in functional and structural MRI’s when they study people with chronic pain. We know much more about chronic pain now than we ever did before because of our brain mapping technology and other tools.

So, what is going on and what can parents do?

First, modern science has shown us that when someone is in pain, there is neural activity in brain/body neural circuits (connections among different parts of the brain, and up/down the spinal cord and out to peripheral nerves in the body).

Our usual tests look for structural, hormonal, infectious, or immunologic causes and when they don’t show up anything pathologic, the doctors call the pain “psychologic” or related to “stress” or “anxiety.” While, by this time, your child is stressed, that doesn’t mean it is the cause of the pain. It certainly has become a contributor to the pain and this is where connecting your child with a psychotherapist can be very helpful. There are strategies your child can learn to feel back in control and not a “victim” of the pain.

Over time, the body’s neurotransmitters or chemicals that impact nerve to nerve transmission as well as mood, anxiety, memory, panic, etc. begin to be depleted. This means that your child’s “pain turn-off system” is no longer working effectively or efficiently. This is where medications that increase your child’s own neurotransmitters like serotonin and/or norepinephrine, dopamine, and others come in. Medications, like antidepressants, can be used in chronic pain to increase levels of these neurotransmitters so your child’s “pain turn-off system” can work better.

Also, pain, anxiety, and depression all interfere with sleep. If your child is not getting sufficient stage III restorative sleep, it’s difficult to function well during the day and the body’s nervous system can’t get back into balance.

The goal of treatment in functional chronic pain (e.g., complex regional pain syndrome, fibromyalgia, chronic daily headaches, irritable bowel syndrome, focal muscular pain like back pain, etc.) is to restore balance to the nervous system from the brain down to the body and from the body up to the brain, as well as to help your child engage with others at school and socially.

Many children need a combination of medication, physical therapy, and psychotherapy. However, we often don’t think about additional healing pathways through creative arts: writing, acting, dance, music, yoga, exercise, art, etc. Studies have shown that involvement in art, music, and creative writing, to name a few, actually alter pain pathways, enhance positive mood, reduce anxiety, and facilitate restorative sleep. Adding a creative art form helps develop other parts of the brain and pulls electrical/neurochemical activity away from pain circuits into other parts of the brain.

The Smart Brain Pain Syndrome

We created a handbook that explains how this works and how these creative brain changers reduce chronic pain. The book is called The Smart Brain Pain Syndrome (Weston, Zeltzer, Zeltzer) and is found on Amazon.

Parents may need to teach their child’s doctors about functional pain, since these concepts are not typically taught in medical school or residency programs. Some doctors do understand that functional pain disorders exist, but don’t know what to do to treat them. Parents need to be advocates for their children and work together to come up with solutions. This book might be a first step.

See our new book to understand chronic pain: CLICK HERE


Lonnie Zeltzer, M.D., is a Distinguished Research Professor of Pediatrics, Anesthesiology, Psychiatry and Biobehavioral Sciences at the David Geffen School of Medicine at UCLA and Immediate Past-Director of the UCLA Pediatric Pain and Palliative Care Program. She is a co-author on the Institute of Medicine report on Transforming Pain in America and is a member of the national steering committee assigned to provide directions for pain research at the National Institutes of Health (NIH).  She has received, among other awards, a Mayday Pain and Policy Fellowship and the 2005 Jeffrey Lawson Award for Advocacy in Children’s Pain Relief from the American Pain Society (APS).  Her UCLA integrative pediatric pain program received a 2009 Clinical Centers of Excellence in Pain Management Award from APS and a 2012 award from the Southern California Cancer Pain Initiative.  She is active in advocacy for pain care and research. She was an invited member of the Institute of Medicine National Expert Panel on pain in American and was a co-author of the IOM publication on the committee findings in 2011. She was an invited member of the Centers for Disease Control (CDC) Special Advisor on The State of Opioids in America. She is also an invited member of the FDA Committee on Analgesia, Anesthesia, and Addiction, where new pain-related drugs are given FDA approval or not, as well as an invited member of the Expert Advisory Committee on Hemoglobinopathies as a pain expert for the National Heart, Lung, and Blood Institute (NHLBI) at NIH.  She is also on an expert panel for the NIH on a national study on a mind-body intervention for teens with fibromyalgia. She is also a member of the national Autism Think Tank as a pain expert in autism. Her research includes yoga, mindfulness, hypnotherapy, and other self-help interventions, including mobile technologies, to help children and adolescents who have chronic pain, as well as understanding biopsychosocial pain mechanisms in irritable bowel syndrome, cancer, sickle cell disease, headaches, dysmenorrhea, and other conditions. She has over 350 research publications on childhood pain and complementary therapies, has written more than 80 chapters, and published her first book for parents on chronic pain in childhood (HarperCollins, 2005) and her second book for parents on chronic pain in children and young adults (Shilysca Press, 2016).