The Center for Managing Chronic Disease says "Chronic Disease is a long-lasting condition that can be controlled but not cured." They are simply wrong. What they should have said is:
Chronic disease cannot be cured by medicines.
How can we know? Let's take a walk with Cesar Millan, the dog whisperer. If you've seen Cesar's popular television show, you will recognize the themes, but you might be surprised at some of the details.