C-reactive proteins (CRPs) are nothing more one of many markers that can be used in giving measurable insight to your level of wellness.
CRPs are produced by liver and increase during times of high levels of inflammation in the body. Among all your traditional labs you can ask your doctor to add a CRP test (if it isn't already included). Elevated levels of inflammation in the body would be indicators for heart disease, rheumatoid arthritis, lupus, crohn's, and other such related issues. This very important marker gives us feedback on how healthy and efficient our body is performing on an internal level. Along with a plethora of other bio markers we can literally plot on a continuum how healthy (or fit) we actually are.
Below is a table of bio makers taken from the "CrossFit level 1 Manual". We can see that almost every measurable value of health can be placed on this continuum from those that are pathological (sick) to the far opposite side "Fit". Those who are in truly "great shape" will reflect markers that are such. The notion is that the further you push your biomarkers towards the right on the continuum, the more of a hedge one will create against disease. Coach Glassman refers to it as "pushing the needle forward".
Just like measuring performance markers (i.e. back squat, mile time, max unbroken pull ups) over time, we can and should measure bio markers over time as well. Bio markers are the truest test of the biological and chemical health of our body. In the world of sport we measure performance markers as the end all be all. Don't get me wrong, performance markers are certainly important, but what your body is capable of is completely dependant on how well your internal system is working. Bio markers tell us this story.
The beautiful part of our body is that it alerts us when there is an issue. In most cases we can see signs years before we are shackled to medication or other life long treatments. Body fat of 25% and an A1C of 7... these are signs we are pre-diabetic (Type-2) if not already. Take any combination of bio markers including and not limited to your white blood cell count, free testosterone, even your bodies PH. We can plot these on a continuum and over time, begin to see trends, and predict future outcomes.