Chronic Pain

What is Pain?

Pain is defined as an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage. Pain can be classified as either “acute” or “chronic”. Acute pain is the most common reason why patients seek medical attention. Acute pain usually has a sudden onset and is associated with tissue damage or painful stimuli (e.g., headache, skinned knee, muscle aches, labor pain). Acute pain is often adaptive because it alerts us to the presence and location of tissue injury and corrects behavior that may be causing or contributing to it. It also reminds us when an injured body part, such as a back or knee, needs time to heal. Chronic pain, on the other hand, refers to the continuation of pain for greater than three months despite treatment and coping efforts by the individual. It has no protective role and is not necessarily associated with tissue damage as viewed from imaging techniques such as MRI or X-ray. Chronic pain can impact all areas of a person’s life and is often associated with functional, psychological and social problems. In addition, chronic pain can have a significant impact on a person’s family and friends.

Types of Pain:

There are two basic types of pain; nociceptive pain and neuropathic pain.

1. Nociceptive Pain - can be divided into two separate categories.

  • Somatic Pain: Somatic pain is caused by the activation of pain receptors in either the cutaneous tissues (body surface) or deep tissues (musculoskeletal tissues). When it occurs in the musculoskeletal tissues, it is called deep somatic pain. Deep somatic pain is usually described as dull or aching but localized. Surface somatic pain is usually sharper and may have a burning or pricking quality. Common causes include post-surgical pain or pain related to a laceration.
  • Visceral Pain: "Viscera" refers to the internal areas of the body that are enclosed within a cavity. Visceral pain is caused by activation of pain receptors resulting from infiltration, compression, extension, or stretching of the chest, abdominal, or pelvic viscera. Visceral pain is not well localized and is usually described as pressure-like, deep squeezing. Examples of visceral pain include pain related to cancer, bone fracture, or bone cancer.

2. Neuropathic Pain - Neuropathic pain is a neurological disorder resulting from damage to nerves that carry information about pain. Neuropathic pain is reported to feel different from somatic or visceral pain and is often described as “shooting”, “electric”, “stabbing”, or “burning”. It may be felt traveling along a nerve path from the spine into the arms and hands or into the buttocks, legs, or feet. Neuropathic pain has very different medication treatment options from other types of pain. For example, opioids (such as morphine) and NSAID’s (such as ibuprofen, COX-2 inhibitors) are usually not effective in relieving neuropathic pain. Treatments for neuropathic pain include certain medications, nerve “block” injections, and a variety of interventions generally used for chronic pain. Examples of neuropathic pain conditions include radiculopathies, neuralgias, failed back syndrome, complex regional pain syndrome, arachnoiditis, and painful neuropathies – (e.g., diabetes or alcohol related).

Pain Measurement:

There is no way to see pain or objectively measure pain. It does not show up on an x-ray or MRI, and people who have pain may look perfectly normal and unimpaired as you walk past them on the street. This is often a source of frustration to the person with chronic pain who frequently hears “you don’t look like you’re in pain!” It is also a source of frustration for physicians who are unable to find structural pathology (e.g., ruptured disc or torn ligament) to account for a person’s pain complaint. Pain is a subjective experience, that is, what one person finds painful may not be painful to another person. Pain patients who visit their physician are often asked to rate their pain on a 0 to 10 scale, with 0 being “no pain” and 10 being “the worst pain imaginable”. This is an accurate and simple way to monitor a person's pain. However, you cannot use this to compare across people. For example, my pain rating of a 7 on a 0 to 10 scale may be a 2 for someone else with a higher pain tolerance.

Treatment of Chronic Pain:

Research consistently indicates that a multidisciplinary treatment approach is the most effective way to address the complex problem of chronic pain. Multidisciplinary treatment teams are generally composed of 2 or more treatment disciplines (e.g., psychology, anesthesiology, neurology, or physical therapy), each with expertise in the assessment and treatment of chronic pain. Members of the team work together in a coordinated manner to provide the best treatment for a patient’s pain.

Psychological Approaches to Pain Management:

Psychological factors such as mood, beliefs about pain and coping style have been found to play an important role in an individual’s adjustment to chronic pain. For example, when pain persists over time, a person may avoid doing regular activities for fear of further injury or increased pain. This can include work, social activities, or hobbies. As the individual withdraws and becomes less active, their muscles may become weaker, they may begin to gain or lose weight, and their overall physical conditioning may decline. This can contribute to the belief that one is disabled. As pain persists, the person may develop negative beliefs about their experience of pain (e.g., this is never going to get better) or negative thoughts about themselves (e.g., I’m worthless to my family because I can’t work). These types of thoughts, along with decreased participation in enjoyable and reinforcing activities, can lead a person to feel depressed and anxious (distress). All of these things can fuel and maintain the pain cycle. The fact that psychological factors can have an impact on the experience of pain does not mean that the pain is "in the persons head" or not real. Most people who report pain are really experiencing it, even if a physical cause cannot be identified.

One particular psychological treatment approach that has been found to be highly effective in helping patients to reduce pain, disability and distress is Cognitive Behavioral Therapy (CBT). CBT for chronic pain management involves modifying negative thoughts related to pain (e.g., this pain is going to kill me, I’m worthless because of the pain, I can’t cope with this pain) and on increasing a person’s activity level and productive functioning. This approach for pain management has been shown to be highly effective in promoting positive cognitive and behavioral changes in individuals with chronic pain. Treatment can be delivered individually or in a group setting.

CBT for pain management is tailored to the individual needs of the patient but may include:

  • Relaxation Training
  • Cognitive Restructuring
  • Stress and Anger Management
  • Sleep Hygiene
  • Activity Pacing

In addition, pain management programs often include a behavioral goal setting componenet in which patients set weekly goals to work towards each week. As part of a multidisciplinary pain treatment team, CBT may incorporate exercise goals set by the physical therapist, or may include recommendations made by the anesthesiologist for taking pain medications at prescribed time intervals.