A large majority of what we know today is because of all of the medical studies and experiments we have been performing. There however is some data from experiments we ran a long time ago. This is data that we would not be able to get now.
This is mainly due to the way the data was acquired. There was some cases in the past where we used prisoners of war to learn about how the body works. Some would consider these medical experiments inhumane. However not being able to experiment on humans really holds us back from learning more about our body.
Doctors all over the world are in great need of the latest medical information. They are the front line of healthcare. Every single day different conditions pop up. If the physicians are not trained to spot them and treat them, that will lead to poor quality of life for the patient.
They also have to be aware of all the latest medications available. You would be surprised how many misdiagnosis occur all over the country. Not only that but how many suffer even more with incorrectly prescribed medication.
While we do have a standard set of testing we can do to diagnose conditions, sometimes these tests do not cover everything.
For example, there is a lot about the heart and the cardiovascular system we do not know about. The brain is even more complicated than that. We need more testing.
As time goes on we will find more cures and we are going to sit here and wish we had found them sooner.