The traditional view is that both conditions are caused by wear and tear. However, more recent evidence suggests that inflammation and chronic pain (even after an injury has healed) may be linked to an immune system response.

According to work presented by Dr Joyce DeLeo, a neuropharmacologist at Dartmouth Medical School, at the annual meeting of the American Association for the Advancement of Science in Philadelphia (February 16, 1998) there is a large biological overlap between the immune system and the central nervous system. Dr DeLeo's paper suggested that some forms of chronic pain persist and become even more intense after healing is apparently complete. This could be because a persistent barrage of nerve signals from a site of nerve or tissue damage may sensitise the nervous system and may even alter the way it functions.

Dr DeLeo and her colleagues believe the immune system is intimately involved in the initiation and maintenance of pain through the production of proteins called cytokines. Their studies have identified at least three proteins interleukin-1, interleukin-6 and tumour necrosis factor alpha which were produced by cells in the spinal cord as a result of nerve injury. One of these, interleukin-6, was shown to generate pain even in the absence of injury. Cytokines were first described in relation to their activities in the immune system. Their actions are known to be complex and affected by the presence of hormones and inflammation. Dr DeLeo now suggests they also have an essential role in the development and survival of the nervous system.

The immune system theory dovetails neatly with more well founded ideas such as inflammation being caused by allergy (which also involves an immune system response). Anyone suffering from bursitis or tendonitis should certainly rule out both food and chemical sensitivities before considering aggressive conventional treatments such as prednisolone, ibuprofen or the more radical "solution" of surgery.

Nutritional therapy has a great deal to offer bursitis sufferers. In one study of 40 patients with bursitis (mostly sub deltoid type), 1000 mcg daily of B12 for seven to 10 days, tapering off to three times weekly for two to three weeks, then one to two times weekly for two to three weeks (depending on rate of progress), all but three patients improved. They experienced rapid relief of pain and subjective symptoms, sometimes within a few hours. Follow up x-rays of cases of calcific bursitis showed considerable reabsorption of calcium deposits (Indust Med Surg, 1957; 26: 20-2). A combination of vitamin C with bioflavonoids, 200 mg three times a day, may ease subpatellar bursitis. In one case, symptoms were all but gone within 72 hours (AM J Digest Dis, 1955; 22: 41-45). Vitamin E also protects against inflammation (J Vitaminol, 1972: 18: 204-9). In addition, low zinc levels may result in the accumulation of free radicals which can cause inflammatory disease. Supplementation may help (Agents Actions, 1986; 18: 103-6).