Medical practice began to greatly improve during the 17th and 18th centuries.  Professional societies were formed in all major European capitals, and scientists shared their research by publishing in journals. 

Medical researchers made some astounding discoveries.  William Harvey determined how blood circulated through the body.  Anton van Leeuwenhoek used a microscope and discovered red blood cells, bacteria, and protozoa. Edward Jenner invented vaccination after discovering the relationship between cowpox and smallpox. 

Clinical practice was revolutionized by Thomas Sydenham who developed a treatment procedure that recognized the importance of environmental considerations and included careful, detailed observation and record keeping. 

Vitamins were discovered and their importance to health recognized.  New drugs, including digitalis, were developed, and vaccination was perfected by Edward Jenner.  Giovanni B Margagni founded pathologic anatomy, and Marie Francois Bichat created the field of histology. 

Still, many of the old practices, like bleeding, continued, and several new and dangerous treatment theories, like homeopathy, flourished for periods of time. 

As the practice of medicine became more professional, many folk healers were prohibited, and male obstetricians began to replace traditional midwives. 

If you would like to learn more about 17th and 18th century medicine, the Karolinska Institute has many interesting links.