A pain persisting for a long time is chronic pain. Usually, pain is called chronic if it lasts more than 12 weeks. It is one of the most common complaints presented in an outpatient setting with every 1 in 5 individuals presenting with some form of chronic pain.
Chronic pain can reduce mobility, making day to day activities difficult and impair the quality of life. People with chronic pain are more susceptible to suffering from depression. You can experience chronic pain in any part of your body.
Causes of Chronic PainIn most cases, the cause of chronic pain is usually a past injury or past surgery, but in some cases, the source of chronic pain is very difficult to find. Sometimes normal aging brings degenerative changes in bones and joints which can lead to chronic pain. Also damage to nerves due to injuries or tumors can result in long-lasting pain. Being obese can also put you at risk of developing chronic pain. Maintaining bad posture over a considerable period has also shown to be a cause of chronic spine pain. Chronic pain may also be caused by underlying diseases such as:
- Chronic fatigue syndrome: Here extreme prolonged tiredness is accompanied by chronic pain
- Inflammatory bowel disease: Group of conditions causing chronic abdominal pain
- Osteoarthritis: Age-related degenerative damage to bones and joints leading to chronic pain
- Fibromyalgia: Chronic pain of bones and muscles.
- Endometriosis: A condition in female where the lining of the uterus grows outside the uterus and is associated with bleeding and chronic lower abdominal pain
- Vulvodynia: Chronic vulval pain in the female that has no obvious cause
- AIDS: Chronic pain in AIDS is caused as a result of peripheral nerve damage and chronic inflammation.
- Multiple sclerosis: A condition where your immune cells attack the lining of nerve fiber leading to nerve damage and chronic pain
- Cancer: Tumors can cause chronic pain by releasing certain chemicals that irritate nerves or by directly pressing upon nerves
Diagnosis and EvaluationFollowing the detailed history, various imaging methods may be advised to diagnose pain. Multiple investigations may be required to rule out any comorbid condition which may be causing pain.
TreatmentThere isn’t a definitive treatment for chronic pain, however, the symptoms of pain can be reduced using over the counter pain killers including acetaminophen, NSAIDs such as aspirin and ibuprofen. NSAIDs and acetaminophen are used as first-line drugs in relieving musculoskeletal pain. Opioids like morphine and codeine are also effective in managing pain especially those secondary to malignancy. Antidepressants also are effective in treating neuropathic pain and chronic musculoskeletal pain. In addition to medications, procedures such as acupuncture may also help relieve pain. Nerve blocks can be done to prevent the transmission of pain impulses to the brain. Passing mild electric current into your muscles also help in pain relief. Surgery may be required sometimes to correct a deformity or defect causing chronic pain.
Recent Advances and Clinical Trials
- Physical therapy: A clinical trial is going on to assess the efficacy of physical therapy in treating chronic pain following traumatic incidences.
- Neurofeedback: A study to assess the effectiveness of neurofeedback, which refers to teaching participants to gain control over their brainwaves, as an effective modality in treating chronic pain. The neurofeedback mechanism is thought to reduce the negative effects associated with chronic pain by teaching the volunteers to gain control over brain signals associated with pain resilience.
- Development of online pain management program: This study using interviews to learn what contents parents and teenagers want in an online intervention program to manage pain in teenagers aims at creating an internet-based program for pain management. Development of this technique would allow teenagers to get access to different pain managing techniques from the comfort of their homes.
- PET/MR Imaging: A study is being conducted to assess the ability of the PET/MR imaging technique to identify and characterize the source of pain. This study is currently in Phase 1 of its clinical trial. It aims at finding a quick and diagnostic method of investigation of chronic pain so that proper therapeutic interventions can be done to treat it.
- Light Therapy: A clinical trial to assess the efficacy of light therapy in managing chronic pain is also being done. Light therapy is thought to produce analgesia( pain relief) and reverse chronic neuropathic pain. Preliminary animal model studies have shown light therapy to cause pain relief mediated through cannabinoid and opioid systems.
- Medical cannabis: A clinical trial of medical cannabis on its efficacy and safety in managing chronic pain is being carried out by treating the volunteers with oil extracts of medical cannabis for six months. This study will help get a better understanding of its effects, success, and failure rates in treating chronic pain with cannabis.
- Study on the effectiveness of duloxetine and desipramine: A comparative study of these common drugs used in treating chronic pain is being carried out for their effectiveness. This study which is currently in the fourth stage of its clinical trial aims at assessing patient adherence to these common anti-pain medications and to advance knowledge in effective pain medications.
- Nerve blocks: In recent years the number of Cesarean Section has increased rapidly. Persistent pain is a known complication following cesarean section which can reduce the quality of life and lead to postpartum depression in mothers. A clinical trial to assess the efficacy and safety of ilioinguinal and iliohypogastric nerve blocks in managing acute and chronic pain following cesarean delivery is being done. Exploring its efficacy could help tackle cases of postoperative pain in settings where there is a shortage of strong opioids for pain management following Cesarean section.
Alexander M. Dydyk, Siva Naga S. Yarrarapu, Till Conermann et al. Chronic Pain. StatPearls Publishing; 2020 Jan- www.ncbi.nlm.nih.gov/books/NBK553030/
Dylan R Addis,Jennifer, J DeBerry, Saurabh Aggarwal. Chronic Pain in HIV. Mol Pain. 2020; 16: 1744806920927276 www.ncbi.nlm.nih.gov/pmc/articles/PMC7252379/