Persistent (chronic) pain is a widespread problem that affects around 8 million people of all ages in the UK (Chronic Pain Policy 2010). In 22% of cases, chronic pain leads to depression, and some 25% of those diagnosed with chronic pain go on to lose their jobs (Chronic Pain Policy 2010). In fact, around £3.8 billion a year is spent on incapacity benefit payments to those diagnosed with chronic pain (Chronic Pain Policy 2010).

The International Association for the Study of Pain has defined pain “as an unpleasant sensory or emotional experience resulting from actual or potential tissue damage…”. Chronic pain may be defined as pain that lasts beyond the usual course of the acute disease or expected time of healing, and it may continue indefinitely.

Typical chronic pain conditions include: osteoarthritis; rheumatoid arthritis; low back, shoulder and neck pain; headache and migraine; cancer pain; fibromyalgia; neuropathic pain (e.g. sciatica, trigeminal neuralgia, post herpetic neuralgia); chronic overuse conditions (e.g. tendonitis); and chronic visceral pain (e.g. irritable bowel syndrome, interstitial cystitis, endometriosis) (Singh 2010).

 

References

Chronic Pain Policy Coalition, 2010. About chronic pain [online]. Available:

http://www.policyconnect.org.uk/cppc/about-chronic-pain

2010 [online]. Available:http://emedicine.medscape.com/article/310834-overview

How acupuncture can help

An early systematic review of acupuncture for chronic pain found very limited evidence to support it (Ezzo 2000), but numerous large, well conducted studies in the last 10 years have substantially changed the picture. Recent reviews have shown that it is more effective than no treatment or usual care for chronic back pain, osteoarthritis, or headache (Sherman 2009). There is also evidence that it is more effective than sham acupuncture for chronic knee pain or headache and, at least in the short term, for chronic back pain (Hopton 2010). Other conditions have been less well researched.

 

For more details of specific research on chronic pain conditions see our other Factsheets: Acupuncture and Back Pain; Acupuncture and Endometriosis; Acupuncture and Frozen Shoulder; Acupuncture and IBS; Acupuncture and GI Tract; Acupuncture and Migraine; Acupuncture and Headache; Acupuncture and Sciatica; Acupuncture and Fibromyalgia; Acupuncture and Osteoarthritis; Acupuncture and Rheumatoid Arthritis; Acupuncture and Dysmenorrhoea; Acupuncture and Neck Pain. There is also evidence from randomised controlled trials and systematic reviews that suggests acupuncture may reduce chronic pain in myofascial syndrome (Shen 2009), chronic shoulder problems (Lathia 2009), chronic prostatitis/chronic pelvic pain syndrome (Lee 2009) and tennis elbow (Trihn 2004). There is preliminary evidence for ear acupuncture in cancer pain (Lee 2005).

 

In general, acupuncture is believed to stimulate the nervous system and cause the release of neurochemical messenger molecules. The resulting biochemical changes influence the body’s homeostatic mechanisms, thus promoting physical and emotional well-being. Stimulation of certain acupuncture points has been shown to affect areas of the brain that are known to reduce sensitivity to pain and stress, as well as promoting relaxation and deactivating the ‘analytical’ brain, which is responsible for anxiety (Wu 1999).

 

Acupuncture may help relieve chronic pain by:stimulating nerves located in muscles and other tissues, which leads to release of endorphins and other neurohumoral factors (e.g. neuropeptide Y, serotonin), and changes the processing of pain in the brain and spinal cord (Pomeranz 1987, Han 2004, Zhao 2008, Zhou 2008, Lee 2009, Cheng 2009);

  • stimulating nerves located in muscles and other tissues, which leads to release of endorphins and other neurohumoral factors (e.g. neuropeptide Y, serotonin), and changes the processing of pain in the brain and spinal cord (Pomeranz 1987, Han 2004, Zhao 2008, Zhou 2008, Lee 2009, Cheng 2009);
  • increasing the release of adenosine, which has antinociceptive properties (Goldman 2010);
  • modulating the limbic-paralimbic-neocortical network (Hui 2009);
  • reducing inflammation, by promoting release of vascular and immunomodulatory factors (Kavoussi 2007, Zijlstra 2003);
  • improving muscle stiffness and joint mobility by increasing local microcirculation (Komori 2009), which aids dispersal of swelling.

The evidence

Research

Conclusion

Systematic Reviews (SRs)

Hopton A, MacPherson H. Acupuncture for chronic pain: is acupuncture more than an effective placebo? A systematic review of pooled data from meta-analyses. Pain Pract2010; 10: 94-102.

 

A synthesis of evidence from systematic reviews on the pooled data of high-quality randomized controlled trials comparing acupuncture to sham acupuncture for chronic pain.  For short-term outcomes, acupuncture showed significant superiority over sham for back pain, knee pain, and headache. For longer-term outcomes (6 to12 months), acupuncture was significantly more effective for knee pain and tension-type headache but inconsistent for back pain (one positive and one inconclusive). The reviewers concluded that the accumulating evidence from recent reviews suggests acupuncture is more than a placebo for commonly occurring chronic pain conditions.
Sherman KJ, Coeytaux RR. Acupuncture for Improving Chronic Back Pain, Osteoarthritis and Headache. J Clin Outcomes Manag 2009; 16: 224-30.

 

A critical review and meta-analysis of the literature on acupuncture for chronic back pain, osteoarthritis and headache. It found that, overall, acupuncture appeared to be superior to no treatment or usual care for people with chronic back pain, osteoarthritis, or headache, but was not clearly superior to sham acupuncture, although the latter is a controversial control group. Acupuncture was also found to have a favourable safety profile, with relatively few side effects. The reviewers concluded that limited evidence suggests that acupuncture is a cost effective treatment, and that it may be particularly valuable for patients who prefer it to other options or are concerned about using analgesic medications.
Lee H et al. Acupuncture for the relief of cancer-related pain–a systematic review. Eur J Pain 2005; 9: 437-44.

 

 

A systematic review that summarised the existing evidence on acupuncture for cancer-related pain from 7 studies. One high quality randomised clinical trial of ear acupuncture showed statistically significant pain relief in comparison with placebo ear acupuncture. All the other studies were either non-blinded (n=2) or uncontrolled clinical trials (n=4), and most suffered from methodological flaws such as inadequate study design, poor reporting of results, small sample size and overestimation of the results. The reviewers concluded that that there are insufficient high quality data to assess the  effect of acupuncture as analgesic adjunctive method for cancer patients
Trinh KV et al. Acupuncture for the alleviation of lateral epicondyle pain: a systematic review.Rheumatology 2004; 43: 1085-90.

 

A systematic review that evaluated the effectiveness of acupuncture as a treatment for lateral epicondylitis. Six randomised controlled trials (4 sham-controlled) were included. All the studies suggested that acupuncture was effective in the short-term relief of lateral epicondyle pain. Five of six studies indicated that acupuncture treatment was more effective compared to a control treatment. The reviewers concluded that there was strong evidence suggesting that acupuncture is effective in the short-term relief of lateral epicondyle pain.
Ezzo J et al. Is acupuncture effective for the treatment of chronic pain? A systematic review. Pain 2000 ; 86: 217-25.

 

A systematic review that assessed the effectiveness of acupuncture as a treatment for chronic pain within the context of the methodological quality of the studies. Fifty one studies met inclusion criteria. Clinical heterogeneity precluded statistical pooling. Results were positive in 21 studies, negative in 3 and neutral in 27. Six or more acupuncture treatments were significantly associated with positive outcomes (p=0.03), even after adjusting for study quality. The reviewers concluded there is limited evidence that acupuncture is more effective than no treatment for chronic pain; and inconclusive evidence that acupuncture is more effective than placebo, sham acupuncture or standard care.
 

Randomised controlled trials

 

Shen YF et al. Randomized clinical trial of acupuncture for myofascial pain of the jaw muscles. J Orofac Pain 2009; 23: 353-9.

 

 

 

A randomised controlled trial that compared real and sham acupuncture for chronic myofascial pain of the jaw muscles in 28 patients. Real acupuncture was given by penetrating the needle through a sticky foam pad at the acupoint. Sham acupuncture was conducted by pricking the skin, without penetration, with a shortened, blunted acupuncture needle through a foam pad placed away from the acupoint. General head and neck pain ratings were obtained before and after treatment on a numerical rating scale. Real acupuncture significantly reduced jaw pain (p=0.04), jaw/face tightness (p=0.04), and neck pain (p=0.04), and significantly increased pain tolerance of the masseter muscle (p=0.001) compared with sham acupuncture. Patients were not able to determine whether they received real or sham acupuncture (p= 0.69). No significant pain reductions were observed in the sham acupuncture group. The researchers concluded that a single acupuncture session significantly reduced most myofascial pain endpoints when compared to sham acupuncture.

 

Lathia AT et al. Efficacy of acupuncture a