A couple of months ago while visiting Trinity College in Dublin, I saw an exhibit in celebration of 400 years of medicine. I was intrigued by the display. It had an original copy of the classic John Gerard's Herbal, or Generall Historie of Plantes. The glass cases also contained tools used by surgeons throughout the years. Notably absent was any mention of the cunning folk. Without saying as much, the exhibit really meant 400 years of male history, namely doctors and physicians. Anyone who was not a learned physician was simply regarded as a "quack".
What many people don't realize is that during the 17th century there were few doctors. Even fewer people could afford the services of a doctor, and those who could often didn't trust them. Most healers were herbalists and/or users of magic. Anthropologists commonly refer to such healers as shamans.
In writing The Dreaming, I discovered that I needed guidance from the era I was writing about. I first looked to Gerard's Herbal, but it wasn't easy getting my hands on a copy. Instead, I turned to Nicholas Culpeper's Complete Herbal. Copies of this book are still easily available, and I was able to get a late 20th-century edition. Don't let a modern edition fool you. Culpeper's words were left intact. The book was, however, typeset in a modern font, making it a little easier to read.
Because my stories are set in Virginia, I also used medicinal guides that showed me what plants the Native Americans used. For instance, when I portrayed an outbreak of small pox, the Natives had no remedies. It was a new disease to the Americas and nearly wiped out the indigenous population. My cunning woman was all too familiar with the disease, and Culpeper let me know that saffron was a good herb of choice. But saffron was limited in Virginia because it had to be shipped from England. Thankfully, all was not lost. An African servant knew of another treatment called variolation.
In another scene, a teenager was bitten by a poisonous snake. In this case, my healer used a knife to make small incisions over the fang marks. She then sucked out the poison. I had been able to verify this treatment was indeed practiced by the Native people in the Virginia area for snake bites and thought it would make a good addition. It's only been within the last thirty to forty years that the method has fallen out of favor with modern emergency crews.
While these are only a couple of examples of 17th-century medicine, I think they give the general idea. There were gifted healers long before modern physicians.