Chronic pain syndromes

Chronic pain is one of the most common reasons for seeing a primary care physician.

Classification of chronic pain may be based on major pain features or by body region: myofascial, musculoskeletal (mechanical), neuropathic, fibromyalgia, and chronic headache syndromes.

One in 3 patients over the age of 65 years is affected by chronic pain, often due to arthritis, osteoporosis with fractures and/or lumbar spinal stenosis. These conditions are treatable and should not be considered part of the normal ageing process. Untreated chronic pain in geriatric patients can result in depression, poor quality of life, and loss of independence.

Some treatments, such as stretching exercises, relaxation techniques, antidepressants, and antiepileptic drugs, are beneficial for a wide variety of chronically painful conditions.

About 25% to 30% of chronic pain patients treated with opioids will demonstrate medicine abuse behaviour.

Acute pain is a common consequence of injury or illness, generally lessening shortly after onset and resolving once healing is complete. Since healing occurs over a maximum of 3 months, pain persisting longer than 3 months is deemed chronic pain or persistent pain. Chronic pain may also occur in patients with ongoing degenerative illnesses, such as rheumatoid arthritis, or other chronic conditions, like migraine or neuropathic pain. Neuropathic pain is characterised by allodynia and hyperalgesia. Allodynia is the perception of non-noxious stimuli as painful. In hyperalgesia, noxious stimuli produce exaggerated or prolonged pain. Pain severity may fluctuate in patients with chronic pain, with times of increased pain or pain flares occurring either in relation to increased activity or stress, or insidiously. Chronic pain occurs due to persistent activation of neural pain pathways and muscle spasm. Chronic pain is discussed here as a syndrome and includes non-malignant conditions without localised or regional causes (such as abdominal pain or pelvic pain).[Figure caption and citation for the preceding image starts]: Acute pain occurs with trauma or illness, decreasing during healing and resolving within 3 months. Chronic pain persists after healing is completed, due to continued activation of neural pain pathways and muscle spasmFrom Marcus DA. Headache and chronic pain syndromes. The case-based guide to targeted assessment and treatment. Totowa, NJ: Humana Press; 2007 [Citation ends].