Short answers, pulled from the story.
Alternative medicine refers to practices that aim for the healing effects of medicine but that by definition lack biological plausibility, testability, repeatability, or supporting evidence of effectiveness. It is not part of evidence-based medicine and does not originate from the scientific method, relying instead on testimonials, tradition, superstition, belief in supernatural energies, pseudoscience, or fraud.
Complementary medicine is used in addition to standard treatments, while alternative medicine is used instead of standard treatments, according to the US Center for Disease Control and Prevention. The UK National Health Service and Cancer Research UK draw the same distinction.
There is a general scientific consensus that alternative therapies lack scientific validation and that their effectiveness is either unproved or disproved. Edzard Ernst, the first university professor of Complementary and Alternative Medicine, concluded that 95 percent of the therapies he studied, including acupuncture, herbal medicine, homeopathy and reflexology, were statistically indistinguishable from placebo treatments.
Much of the perceived effect comes from the placebo effect, from a condition resolving on its own, or from regression toward the mean, where an extreme symptom is naturally followed by a less extreme one. Reporting bias and the lack of blinding in studies can also make alternative therapies appear effective when the objective effect is non-existent or harmful.
Yes, alternative medicine can be dangerous, both directly and by delaying effective treatment. Between 2001 and 2003, four children died in Australia because their parents chose naturopathic, homeopathic, or other alternative medicines instead of conventional therapies, and some remedies such as amygdalin can cause cyanide poisoning or interfere with chemotherapy and anesthetics.
The National Center for Complementary and Integrative Health has spent more than 2.5 billion US dollars on alternative medicine research since 1992 without demonstrating efficacy. As of 2011 the NIH Office of Cancer Complementary and Alternative Medicine had given out grants of around 105 million dollars a year for several years.
Functional medicine is a form of alternative medicine created by Jeffrey Bland in the early 1990s and described as a rebranding of complementary and alternative medicine and a form of quackery. In 2014 the American Academy of Family Physicians withdrew course credits for functional medicine courses after identifying some treatments as harmful and dangerous.