When blood sugar stays too high for a long time, it triggers harmful stress and inflammation in the body that directly damages the kidneys. This process speeds up scarring in the kidney filters, causes protein to leak into urine, and gradually reduces how well the kidneys work.

High blood sugar in diabetes turns on harmful inflammation pathways in the body — damaging blood vessels, kidneys, and the heart — by creating toxic molecules and activating immune switches like NF-κB and NLRP3.

When someone has both type 2 diabetes and chronic kidney disease, the two conditions make each other worse in a vicious cycle. High blood sugar damages the kidneys and blood vessels, while failing kidneys make it harder for the body to use insulin and process diabetes medications, leading to more severe health problems and higher medical costs worldwide.