What is chronic pain?
Chronic pain is pain that is ongoing, keeps returning, or lasts longer than the normal course of healing. It can last long after the injury or illness that first caused it is gone. Chronic pain can last from several months to many years. It has a negative effect on a person’s well-being and ability to perform everyday activities.
Symptoms and Causes
What causes chronic pain?
There are many possible causes of chronic pain. According to the Institute for Clinical Systems Improvement, chronic pain can be grouped into four main types.
- Neuropathic (nerve-related) pain: This is pain caused by damage to or malfunctioning of the somatosensory system. This is the system made up of sensory receptors and neurons (nerve cells) in the central nervous system and the peripheral nervous system (outside of the central nervous system). One example of neuropathic pain is sciatica (pain in the back, hip, and upper thigh related to the sciatic nerve).
- Muscle pain: Problems with the skeleton’s muscles are a frequent cause of chronic pain. Myofascial pain (muscle tissue pain) can affect areas such as the lower back, hips, legs and feet, neck, shoulders, arms, and trunk of the body. It often occurs after an injury or following repetitive motions.
- Inflammatory pain: Inflammatory agents trigger main sensory nerves that send pain signals to the spinal cord. Causes include arthritis, tissue injury, or infection. It may also be due to conditions that occur after surgery. Symptoms may include redness, warmth, and swelling at the site of the pain.
- Mechanical/compressive pain: Mechanical pressure or stretching activates nerve cells that are sensitive to pain. Causes may include fractures, disc degeneration, or compression of tissue by tumors, cysts, or bony structures.
A person may have multiple conditions that cause chronic pain (for example, cancer and osteoarthritis).
In some cases, people have chronic pain when there is no apparent underlying cause that can be found. This is known as psychogenic pain. Psychogenic pain does not mean that a person is “making it up” or “crazy.” The pain is very real. However, psychological factors such as anxiety, depression, excessive stress, or environmental factors are the major explanations for this type of chronic pain.
Other types of chronic pain with no apparent cause may result from changes in the central nervous system. Sometimes after a disease or injury occurs, the central and peripheral nervous systems undergo abnormal changes in their structure and function. These changes may make people extra-sensitive to pain and may produce sensations of pain well after the injuries are healed. These dysfunctional changes in the central nervous system are known as central sensitization. Once the central nervous system has become hypersensitive to pain, it is difficult to reverse the hyperactivity and the associated persistent pain.
Diagnosis and Tests
How is chronic pain diagnosed?
There is no way to objectively measure pain. Only the person with chronic pain can provide a description of how much pain he or she is feeling. The doctor will ask where the pain is located, how long it has been going on, and whether it is sharp or dull, constant, or occurs off and on. Sometimes a patient will be asked to rate how bad the pain is by using a numerical scale and giving more details. The doctor will do a physical exam and may order additional diagnostic tests, including:
Laboratory tests to analyze blood, urine, and/or fluid from the spinal cord and brain.
Musculoskeletal or neurological exams to assess reflexes, sensation, balance, and coordination.
- Magnetic resonance imaging (MRI) to obtain scans of the brain, spinal cord, and other structures.
- X-rays to obtain images of the bones, joints, and other structures.
- Electromyography to test muscle activity.
- Nerve conduction studies to record how well nerves are working.
Management and Treatment
How is chronic pain treated?
Although no single cure is available for chronic pain, there are many ways to treat and manage it. The first step should be to treat any underlying conditions that may cause pain. These treatment methods will vary according to the specific disease or medical condition. The treatment also will depend on the type of chronic pain involved. It is recommended that a team of healthcare professionals work with the patient to develop a comprehensive plan for treating and managing pain, instead of relying solely on medications. The focus should be on development of self-management skills, along with lifestyle changes and efforts to improve physical and mental health. The plan should include psychological and behavioral therapy.
Drug treatments for chronic pain
- Analgesics (pain relievers): The use of pain relievers is the most common method for treating chronic pain. These drugs do not work in all cases, however.
- Non-narcotic pain relievers: Nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin, ibuprofen, naproxen, or COX-2 inhibitors may be useful when the pain is mild or moderate. There are many other types of NSAIDs. NSAIDS work by blocking pain near the pain site. Acetaminophen is a non-NSAID pain reliever that works by blocking pain in the brain.
- Opioids, opioid-like agents, or combinations of opioids and non-narcotic analgesics: Any of these may be prescribed to reduce pain. Opioids work in the brain, central nervous system, and other areas of the body to block the sensation of pain. Because of the way they work, they have many negative side effects. Opioids are most useful with acute pain such as pain after surgery or trauma and are usually reserved for cases of chronic pain when other pain relievers are not effective and when the negative side effects are manageable.
- Topical products: Over-the-counter creams and ointments containing capsaicin (a substance generating heat) may be applied directly to the skin three to four times per day. Lidocaine (a local anesthetic) creams or patches also can treat chronic pain.
- Antidepressants: Many chronic pain patients may benefit from taking anti-depressant drugs. This is because the same chemicals linked to depression also play a role in chronic pain. Types of antidepressants prescribed include tricylic antidepressants, selective serotonin reuptake inhibitors (SSRIs), and others.
- Anticonvulsants (anti-epileptics): These drugs may be used to treat various neuropathic pain conditions. Such conditions include nerve injuries and diabetic nerve pain.
- Sedatives/anti-anxiety agents: These may be prescribed for short-term treatment of sleep problems including insomnia (sleeplessness).
- Muscle relaxants.
- Antirheumatics/immunological agents.
- Botulinum toxins.
Non-drug treatments for chronic pain
- Exercise: Light to moderate exercise may help improve blood and oxygen flow to muscles and reduce stress. It may be especially helpful for people with low back pain, arthritis, psychogenic pain, and many others.
- Heat and/or cold application: Applying heat and/or cold regularly to a sore area via a safe mechanism (such as hot or cold packs that have temperature limits built in to prevent burning or freezing skin) can be very effective for treating many types of pain.
- Acupuncture: Acupuncture done by a trained therapist can provide relief for all types of chronic pain.
- Massage: Massage therapy has been shown to be effective for muscle and mechanical pain and may be useful for other kinds of chronic pain as well.
- Spinal cord stimulation: Electrodes are placed inside the epidural part of the spinal cord. The patient can send electrical pulses to the spinal cord using an implanted electrical pulse generator. The electrical impulses interrupt the pain signal to the brain providing relief.
- Deep brain stimulation: This technique is only used to treat chronic pain in cases that do not respond to more conservative treatment. It requires surgical stimulation of areas of the brain, usually the motor cortex or thalamus.
Psychological and behavioral treatments for chronic pain
- General mental health and behavioral counseling: Mental health professionals such as psychotherapists, psychologists, and social workers can work with patients. Goals are for the patients to improve coping skills and develop strategies to reduce stress, anxiety, depression, and sleep problems.
- Cognitive behavioral therapy (CBT): This form of treatment focuses on gaining coping skills, such as how to identify and change negative thoughts and learning relaxation techniques. These, in turn, will help the person gain more control over his or her emotions and moods as well as more control over feelings of pain.
- Fear-avoidance training: People with chronic pain may avoid movement and activity and not get enough activity due to their fear of re-injury or pain. Treatment includes education, instruction on active pain management techniques, and routine exposure to activities that the patient may have avoided in the past.
Mind-body treatments for chronic pain
- Relaxation techniques: These include breathing exercises and other relaxation method.
- Mindfulness training.
- Biofeedback: Patients can learn this technique to control the body's functions, including heart rate and muscle tension.
- Music: Listening to different types of music has been shown to change brain waves and can be very effective in treating pain.
- Art therapy.
- Pet therapy.
- Reiki: A technique in which the therapist can channel energy into the patient by means of touch in order to activate the natural healing processes to help with pain.
- Guided imagery: This self-care technique is highly effective in significantly reducing anxiety and pain.
- Aromatherapy: Different aromas can be used to reduce pain and anxiety.
- Healing Touch: A healing energy therapy that uses a practitioner’s hands to intentionally influence energy fields to promote healing through reduction of pain, anxiety, and fatigue and to improve overall emotional health. Has been used for abdominal pain as well as pain from cancer, sickle cell disease, and heart surgery.
Outlook / Prognosis
What is the outlook for people with chronic pain?
Chronic pain can be successfully treated if people take actions to address it. Advances in neuroscience are likely to result in better treatments and more treatments in the future.
What are some self-management tips for a person living with chronic pain?
- Learn how to relax through deep breathing and other stress management techniques.
- Set achievable goals and don't overdo it on good days. Learn to pace yourself.
- Focus on positive thoughts.
- Set a daily schedule that includes time for rest, exercise, and relaxation.
- Join a chronic pain support group and/or find the nearest meeting for the American Pain Society.
- Know your medicines, including expected benefits and side effects. When the costs of medicines are greater than the benefits, ask your doctor if there’s a better choice. A medicine is working if it helps you have a normal mood and activity level. If the medicine decreases your desire or ability to be active, ask your doctor about other choices.
- Take all medicines as they are prescribed, but don’t hesitate to ask questions. Ask if the medicine that is prescribed is meant to treat symptoms or to manage an underlying disease.
- Cut down on alcohol, or stop drinking alcohol completely. Pain often disrupts sleep, and alcohol can further upset the sleep cycle.
- Quit smoking. Cigarettes can interfere with healing and are a risk factor for developing many diseases, including degenerative disc disease (a leading cause of low back pain).
To manage chronic pain, all aspects of a person’s physical and emotional health must be considered. When chronic pain is managed effectively, a person can return to a more productive and fulfilling lifestyle.