Medical quackery and "alternative medicine" are so vastly widespread world-wide that they should be considered a major social problem, not just a popular form of pseudoscience. In developed countries, a significant fraction of the population, typically roughly 30%, turns to quacks for some or all medical needs, while in second- and third-world nations, quackery is typically the only treatment available to the poor, and only the tiny minority of very rich people can afford science-based, effective medical care. The World Health Organization has become a shameless and dangerous promoter of all forms of medical quackery. Here is a reliable internet resource on this vast topic.  Here is the course fact sheet on quackery. The latest and greatest arrow in the quiver of quackery is social media... fake news! When a new wrinkle in quackery appears, it can now spread like wildfire world-wide in a matter of days.

While some quacks invent their own brand of quackery, many claim to follow some ancient and magic-based "healing tradition." These traditions are entirely pre-scientific, dating back hundreds or even thousands of years. Many don't seem to realize that medicine and medical practice became firmly science-based only after World War 2, the end of which is only 78 years in the past, and in the last half of the 20th Century and the first two decades of the 21st, medical progress has been breathtakingly rapid. There is no alternative to science, and so there is no alternative to science-based medicine. It is the only game in town. Medical quackery generally involves four major themes. First, bacteria and viruses have no role in disease and probably do not even exist. (Quacks have opposed vaccines as long as inoculation and vaccines have existed.)  Second, any disease is actually due to some "imbalance" of some aspect of the body, often imaginary, and both diagnosis and treatment are purely symbolic and magical, depending on imaginary and unobservable connections between one part of the body and another. Thus, one famous field of quackery, reflexology, claims that any and all diseases can be treated and cured by massage of your feet. Third, the same treatment is prescribed for many different, completely unrelated real ailments, and the treatment is nonfrightening and noninvasive, as is the diagnosis. One simple but traditional mystical therapy or procedure or herb cures all. Fourth, quacks may tend to justify their treatment by appealing to something the patient knows nothing about but sounds new and exciting... the treatment is a newly discovered application of quantum healing, or energy healing, or whatever. Or as an alternative, the quack may justify his therapy by appeal to "ancient wisdom," the more ancient the better. Centuries old is good, thousands of years old is much better.  The tradition need not even exist, but it usually does, as a minor footnote in ancient tomes of magical rituals.  The USA is a pot of gold for most forms of quackery, with so many poorly-educated and poorly informed citizens,  at least some of whom have significant amounts of disposable cash!  It is very important to understand that the quack diagnostic procedures are just as magical and mystical as the corresponding quack treatments!  Real diseases are not of much interest to quacks, unless the disease is of such a nature, and so far advanced, that modern medicine cannot hold out much hope for the patient, since no medical intervention is possible---advanced pancreatic or ovarian cancer provide examples I have personally witnessed. That situation is made to order for the quack, and cancer quacks abound, with sure-fire treatments for any and all forms of cancer, no matter how aggressive.

One major selling point of most quackery is that it is non-threatening. No needles, no unpleasant diagnostic testing--- in fact no diagnostic procedures at all. A chiropractor or osteopath may just give you a good massage. But quackery can involve scary or dangerous procedures. The dominant form of medical quackery in Europe and the US from the 1600s to the late 19th Century was Bleeding, aka Bloodletting, a treatment invented circa 400 BCE in ancient Greece, by followers of Hippocrates. A sick person had his arms slashed so that he or she would bleed copiously, in order to balance the imaginary unbalanced humors. However, this extreme procedure was gradually replaced by the more benign but equally useless Cupping, in which a suction cup was used to produce a relatively painless temporary blister! However, cupping and bleeding can be combined by making many small punctures and then using suction to generate much bleeding!  Similarly, a dismal form of primitive healing magic inherited from ancient China involved sticking many long, thin, sharp needles into completely imaginary "meridians," to stimulate blocked flow of the vital essence, or something. This was good old acupuncture. But if you are scared of needles, no worries, because for US customers a new, no-needle variant came into existence, which just used gentle finger pressure on those same imaginary meridians... say hello to acupressure!

In the 20th and 21st Centuries, there have been many crossovers between medical quackery and other pseudosciences... pseudosciences you would think would have no connection to treatment of disease! We have seen how Transcendental Meditation spun off a branch of quackery, Ayurvedic Medicine. Even such a vague, seemingly harmless social fad as Mindfulness is now spinning off wild quack claims.  We will see a number of other examples.  Warning people about how to identify quackery and what its dangers are doesn't seem to be effective in the general case... because quackery always offers the easiest path.  Want to lose weight and still eat as much as you want?  There's a fad diet designed just for you!   Did you see something on the internet that makes you think you might have cancer?  Instead of going to the doctor and maybe getting scary news and facing surgery, go to that friendly guy down the street who advertises in various places (so he must be legit!) and says he has discovered how to use "body-quantum entanglement healing" to cure any disease whatsoever, not  just cancer!  Did you know there is a special natural supplement that you can take as a tablet once a day, and it will protect you against any known disease?  It turns your immune system into a perfectly tuned, infallible thing!  How about this guy all your friends seem to be going to, who can relieve stress and eliminate fatigue and improve everything from sleep to sex, just by crafting you a special gemstone tuned specifically to your personal vibration?   A classic example of a pill a day keeping disease away is the multivitamin capsule, which has been overwhelmingly popular since the 1950s, even as repeated large-scale medical studies consistently have demonstrated that it has no health benefits whatsoever.