The American Medical Association become first prepared in 1846. Its purpose is believed to have been to improve the quality of medical care. In fact it was intended to make it possible for MDs to charge more for their services through reduction in competition. Which of course was possible only with the help of the government. Same basic principles as any other professional organization or labor union. Businesses organized themselves first, organized labor came later when FDR welcomed their support and provided legislation favorable to organized labor. Almost the same thing is done in other professions where obtaining a government license reduces competition and allows for higher income. All of these organizations work to increase member income through a restriction of the number of providers of service available. No different from organized labor winning higher wages and benefits through restrictions on who the employer can hire and how much the salary is... As with businesses and licensed businesses, the "consumer" is someone who acts as the employer. Forced to pay high prices had to do with labor unions. Professional organizations are better off defrauding us with respect to the value of our services than the fees we charge for our services. But in practice the aim of any organization is to get "more" for its members.
The AMA used the power of the government to ban medical education and who could claim the title of "doctor". The AMA described "allopathic medicine", whereas another cluster believed that health needed the follow of "osteopathic" medicine that included dealing with the spine, among other aspects of medical care. Is. There were also chiropractors who worked solely with the spine. These were the three major groups. There were also smaller groups that worked on a variety of principles. There were also Christian scientists who believed that the right kind of prayer would heal you. As time has gone on for various Asian practices, acupuncture is perhaps the best known. Trust is clearly a factor in what works and what doesn't.
In the 19th century there were a lot of "patented" drugs that often contained alcohol mixed with. Someone even came up with a "diet system" that actually used tapeworm eggs. They offered a guarantee that you would lose weight, which of course everyone who took the tapeworm egg did. Almost anything was allowed, without any government agency. Opium and were available in every drugstore. Pharmacists used to mix different medicines together and make their own "medicines". People also trusted their neighborhood pharmacists more than the local doctor because doctors could charge more for their services, even if the medicine was the same as you could get from a pharmacist at no extra charge. It wasn't until 1938 that the AMA won the legal right to require a doctor's prescription to purchase the drug. Taking pharmacists out of the picture and raising prices to the consumer. In some other countries pharmacists can still prescribe and sell drugs, with the governments of these countries more concerned about the welfare of the people as opposed to the US where the government is, for all practical purposes, "friends" of those who are American's. People exploit for their own benefit.