Since alternative treatments are used instead of conventional regimens, they can be medically dangerous and can delay standard medical care. Complementary therapies, on the other hand, are used in conjunction with mainstream treatment and are much more common. Complementary therapies become alternative only when promoted as 'stand-alone' remedies for serious illnesses. It is not the therapy itself, but its goal or the intention behind its use, that defines a regimen as alternative versus complementary.
