What Is Chronic Pain?
Acute pain alerts you to the presence of injury and is usually limited to less than 30 days. Chronic pain is characterized by pain signals being transmitted and, in many cases, being amplified for weeks, months, and even years. Chronic pain is usually defined as pain lasting longer than three months. Still others characterize it as pain persisting longer than reasonably expected for whatever injury is involved.
In this article, chronic pain will be defined as pain persisting longer than three months. The pain can be graded mild, moderate, or severe. It can be unceasing or sporadic. It can also be mildly irritating to severely disabling. Chronic pain is seen more often in women.
Chronic pain is prevalent and affects about 100 million in the U.S. It can be an enigma due to its complicated natural history, vague etiology, and poor response to treatment. There can be an inciting mishap, an ongoing cause of pain, or an absence of both. Chronic pain is commonly rooted in musculoskeletal, neurologic, urologic, gastrointestinal, or reproductive disorders. It also has associations with psychological disorders such as major depression, conversion disorder, hypochondriasis, and somatization disorder. Common areas for chronic pain are joints, back, head, neck, shoulders, and the pelvis.
Key factors a physician will want to know about when taking a pain history include:
- The location of pain
- Precipitating factors
- Alleviating factors
- Quality of pain
- Radiation of pain
- Intensity of pain
A detailed physical examination is also helpful at pinpointing potential causes of chronic pain. Attention should be paid to Waddell signs, which refer to disability that is out of proportion to physical impairment and objective findings on examination. Imaging studies such as X-ray, computed tomography (CT), and magnetic resonance imaging (MRI) can also be utilized in the assessment of chronic pain.
Symptoms associated with chronic pain include fatigue, difficulty sleeping, suppression of the immune system, avoidance of activity, and disability. Also mood changes such as depression, fear, hopelessness, irritability, stress, and anxiety can be linked to chronic pain. The emotional toll it takes can make pain worse.
Causes Of Chronic Pain
Various musculoskeletal, neurologic, urologic, gastrointestinal, and reproductive disorders can contribute to chronic pain.
Musculoskeletal disorders leading to chronic pain include:
- Rheumatoid arthritis
- Lyme disease
- Disc herniation
- Spinal compression fractures
- Poor posture
- Muscular strains and sprains
- Chronic overuse syndromes such as tendinitis and bursitis
Neurologic disorders causing chronic pain include:
- Brachial plexus traction injury
- Spinal stenosis
- Cervical radiculopathy
- Migraine headaches
- Muscle tension headaches
- Chronic daily headaches
- Temporomandibular joint dysfunction (TMD)
Urologic disorders predisposing to chronic pain include bladder cancer, chronic urinary tract infection (UTI), interstitial cystitis, kidney stones, prostatitis, Peyronie disease, testicular torsion, and urethral stricture.
Gastrointestinal disorders associated with chronic pain include gastroesophageal reflux disease (GERD), peptic ulcer disease (PUD), pancreatitis, diverticulitis, bowel obstruction, irritable bowel syndrome (IBS), colitis, chronic constipation, and inflammatory bowel disease (IBD).
Reproductive disorders leading to chronic pain include endometriosis, adhesions, salpingitis, chronic ectopic pregnancy, pelvic congestion syndrome, fibroids, cervical stenosis, vulvodynia, and genital prolapse.
Other causes of chronic pain include injuries, trauma, and infections. Some afflicted with chronic pain have no apparent cause for the pain. Neuritis, or nerve inflammation, is a cause in a great many with no discernible cause for their chronic pain.
Some established risk factors for chronic pain include stress, anxiety, fatigue, depression, and anger. The risk factors contributing to chronic pain may have to do with the inhibition of endorphins, natural pain-relieving hormones. Clinical studies have shown that those diagnosed with chronic pain have lower than normal levels of endorphins in their cerebrospinal fluid (CSF).
Chronic pain takes a toll both physiologically and psychologically. It can lead to depressed mood, poor sleep, decreased libido, substance abuse, dependent behavior, and disability. Most certainly, chronic pain restricts the activities of daily living and decreases the quality of life in those who have been diagnosed. Furthermore, chronic pain can be a contributor to family or marital problems, unemployment, and adverse side effects attributed to medical therapy.
Treatments For Chronic Pain
Treatments for chronic pain fall into three general categories:
- Procedures or surgeries
Medications are a cornerstone of treating chronic pain. Non-steroidal anti-inflammatory drugs (NSAIDs) that have been used for the treatment of chronic pain include ibuprofen (Advil, Motrin), naproxen sodium (Naprosyn, Anaprox), diclofenac (Voltaren, Cataflam XR), indomethacin (Indocin), and ketoprofen. These medications act to reduce inflammation, thereby reducing pain. Analgesics such as acetaminophen (Tylenol), oxycodone, hydrocodone, and fentanyl (Duragesic) are also utilized. Narcotic analgesics like oxycodone, hydrocodone, and fentanyl should only be used in the short-term due to concerns of abuse and dependence.
Antidepressants are also commonly used in the treatment of chronic pain. Tricyclic antidepressants (TCAs) include drugs such as amitriptyline (Elavil) and nortriptyline (Pamelor). Duloxetine (Cymbalta) and venlafaxine (Effexor) are selective serotonin norepinephrine reuptake inhibitors (SNRIs), a class of antidepressants used to treat chronic pain. The selective serotonin reuptake inhibitors (SSRIs) fluoxetine (Prozac), sertraline (Zoloft), and paroxetine (Paxil) are also utilized. Anticonvulsants are also of value in the treatment of chronic pain. Gabapentin (Neurontin) and pregabalin (Lyrica) are examples.
Various procedures and surgeries are also available for the treatment of chronic pain. Nerve blocks, especially in a sympathetic nervous system distribution, are effective therapeutic tools. This procedure involves the injection of an anesthetic and a corticosteroid near nerves that are responsible for the chronic pain. This treatment serves to block pain signaling and reduce inflammation.
Spinal cord stimulation is another option and requires the implantation of a stimulator device that emits electrical impulses that override pain signaling. Intrathecal morphine pumps require the implantation of a pump that delivers medication.
Radiofrequency ablation is minimally invasive and uses heat to deal with affected nerve tissue. In this procedure, an electrode is inserted and used to deliver an electrical current to create highly localized heat that causes impairment to or destroys nerve tissue, thus disrupting pain signals.
Adhesiolysis is another treatment option that is especially helpful for chronic neck and back pain. It involves the use of medications to destroy adhesions, or scar tissue, that may be irritating nerve roots and causing pain.
Vertebroplasty and kyphoplasty help treat chronic back pain attributed to spinal compression fractures. These fractures occur most often in people with osteoporosis (thinning and weakening of bone). Both are safe and effective procedures. Vertebroplasty requires the injection of special cement into the affected areas of the spine, which restores and straightens the spinal column.
Kyphoplasty is similar and is done by inserting a balloon into the spinal fracture creating a cavity into which cement is injected. Kyphoplasty is chosen more often than vertebroplasty due to the low risk of cement leakage, brief operative times, and decreased radiation exposure. The bulk of pain relief is achieved within the first 48 hours of treatment with both procedures. Both kyphoplasty and vertebroplasty should be performed within eight weeks of acute fracture for the best outcomes. Both procedures effectively decrease pain and help patients restore some of the lost mobility in the spine.
Steroid injections, cervical and epidural, can also provide long-term relief of pain in some. They may be repeated for a total of no greater than three times in a period of 12 months.
Many therapies can also be integrated into the treatment of chronic pain. Physical therapy (PT) techniques utilize modalities such as hot or cold therapy, stretching, positioning, massage, traction, ultrasound therapy, manipulation, and transcutaneous electrical nerve stimulation (TENS). Likewise, chiropractic manipulation can be used to treat a variety of musculoskeletal conditions. Occupational therapy (OT) teaches desensitization techniques. Recreational therapy utilizes enjoyable activities that culminate in decreased pain. Vocational therapy can give an idea of work capacity and targeted work hardening activities.
Psychophysiologic therapies include areas such as reassurance, counseling, biofeedback, relaxation training, acceptance and commitment therapy (ACT), cognitive behavioral therapy (CBT), and stress management. Relaxation training is just as effective as biofeedback. ACT may be more beneficial than CBT.
Acupuncture is thought of as an alternative therapy for chronic pain. It involves inserting thin needles into the skin at agreed upon strategic locations. It is a key component of traditional Chinese medicine. Acupuncture balances the flow of energy, or chi, through pathways in the body. It is thought to decrease inflammation and increase the release of endorphins. Types of acupuncture include traditional needle, manual, laser, and electroacupuncture.
Pain has two general categories—acute and chronic. Acute pain signals injury and generally resolves in less than 30 days as a person heals. Chronic pain refers to pain persisting longer than three months. It can last months to years. Chronic pain can be mild to severe, annoying to debilitating, and continuous to intermittent.
The cause of chronic pain can be an injury, infection, or ongoing disease. In many, the cause of pain is unknown, or idiopathic. Some of the major causes of chronic pain include headaches, low back strain, arthritis, cancer, and neuropathy (disease of nerves). Various musculoskeletal, neurologic, urologic, gastrointestinal, and reproductive disorders can contribute to or lead to chronic pain. Risk factors for chronic pain include stress, anxiety, fatigue, depression, and anger.
Chronic pain can be treated with medications, procedures or surgeries, and various forms of therapy. Classes of medications used to treat the disease include analgesics, non-steroidal anti-inflammatory drugs, and antidepressants. Procedures or surgeries that can be helpful include nerve blocks, adhesiolysis, radiofrequency ablation, vertebroplasty or kyphoplasty, steroid injections, spinal cord stimulation, and intrathecal morphine pumps. Various forms of therapies used to treat chronic pain include physical, chiropractic, occupational, recreational, and vocational. Psychological therapies include reassurance, counseling, biofeedback, relaxation training, acceptance and commitment therapy, cognitive behavioral therapy, and stress management. Acupuncture is also utilized as an alternative therapy for this condition.
Overall, chronic pain may take an extensive toll on a person’s life. It can affect activities of daily living and tremendously decrease quality of life. The condition is best treated with a multidisciplinary approach including professionals such as physicians, psychologists, and therapists.
1. Abdi S, Datta S, Trescot AM, Schultz DM, Adlaka R, Atluri SL, Smith HS, Manchikanti L. Epidural steroids in the management of chronic spinal pain: a systematic review. Pain Physician. 2007;10(1):185-212.
2. Cheng J, Pope JE, Dalton JE, Cheng O, Bensitel A. Comparative outcomes of cooled versus traditional radiofrequency ablation of the lateral branches for sacroiliac joint pain. Clin J Pain. 2013;29(2):132-137.
3. Choi E, Nahm FS, Lee PB. Evaluation of prognostic predictors of percutaneous adhesiolysisusing a Racz catheter for post lumbar surgery syndrome or spinal stenosis. Pain Physician. 2013;16(5):E531-536.
4. Garcea G, Thomasset S, Berry DP, Tordoff S. Percutaneous splanchnic nerve radiofrequency ablation for chronic abdominal pain. ANZ J Surg. 2005;75(8):640-644.
5. Glazov G, Yelland M, Emery J. Low-dose laser acupuncture for non-specific chronic low back pain: a double-blind randomised controlled trial. Acupunct Med. 2013; in press.
6. Goz V, Errico TJ, Weinreb JH, Koehler SM, Hecht AC, Lafage V, Qureshi SA. Vertebroplasty and kyphoplasty: national outcomes and trends in utilization from 2005 through 2010. Spine J. 2013;in press.
7. Li LH, Sun TS, Liu Z, Zhang JZ, Zhang Y, Cai YH, Wang H. Comparison of unipedicular and bipedicular percutaneous kyphoplasty for treating osteoporotic vertebral compression fractures: a meta-analysis. Chin Med J (Engl). 2013;126(20):3956-3961.
8. Manchikanti L, Cash KA, McManus CD, Pampati V. Assessment of effectiveness of percutaneous adhesiolysis in managing chronic low back pain secondary to lumbar central spinal canal stenosis. Int J Med Sci. 2013;10(1):50-59.
9. Manchikanti L, Cash KA, Pampati V, Wargo BW, Malla Y. Management of chronic pain of cervical disc herniation and radiculitis with fluoroscopic cervical interlaminar epidural injections. Int J Med Sci. 2012;9(6):424-434.
10. Park Y, Ahn JK, Sohn Y, Jee H, Lee JH, Kim J, Park KD. Treatment effects of ultrasound guide selective nerve root block for lower cervical radicular pain: A retrospective study of 1-Year follow-up. Ann Rehabil Med. 2013;37(5):658-667.
11. Von Korff MR. Long-term use of opioids for complex chronic pain. Best Pract Res Clin Rheumatol. 2013;27(5):663-672.
12. Wasserman RA, Brummett CM, Goesling J, Tsodikov A, Hassett AL. Characteristics of chronic pain patients who take opioids and persistently report high pain intensity. Reg Anesth Pain Med. 2013; in press.