These magnets may be worn for just a few minutes or for weeks, depending on the condition being treated and the practitioner. Proponents state the magnetic fields produced from the negative pole of the magnet have healing powers. Negative magnetic fields are thought to stimulate metabolism, increase the amount of oxygen available to cells, and create a less acidic environment within the body. Conditions diagnosed or treated include arthritis, cancer, circulatory disorders, diabetic neuropathy (nerve disease), fibromyalgia, HIV/AIDS, immune dysfunction, infection, inflammation, insomnia, multiple sclerosis, muscle pain, neuropathy, pain, rheumatoid arthritis, sciatica, stress and to increase energy and prolong life. Although there are anecdotal reports of healing with magnetic therapy, available scientific evidence does not support these claims. The U.S. Food and Drug Administration (FDA) considers magnets harmless and of no use for medical purposes.