Alternative medicine, fringe medicine, pseudo medicine or simply questionable medicine is promotion or use of practices which are unproven, disproven, impossible to prove, or excessively harmful in relation to their effect — in the attempt to achieve the healing effects of medicine. It differs from experimental medicine in that the latter employs responsible investigation and is discarded when shown ineffective. The scientific consensus is that alternative therapies either do not, or cannot, work. In some cases, laws of nature are violated by their basic claims; in others the treatment is so much worse that its use is unethical. Alternative practices, products, and therapies range from those which are simply ineffective to those having known harmful and toxic effects. Alternative therapies may be credited for perceived improvement through placebo effects, decreased use or effect of medical treatment (and therefore either decreased side effects; or nocebo effects towards standard treatment), or the natural course of the condition or disease. Alternative treatment is not the same as experimental treatment or traditional medicine, although both can be misused in ways that are alternative. Alternative or complementary medicine is dangerous because it may discourage people from getting the best possible treatment and may lead to a false understanding of the body and of science.