As an RN nurse, I realized that whenever a diabetic patient get injured their wound doesn’t heal faster why?

You won't like this, but go back to your pathophysiology r/t diabetes, it's effect on the body systems and then use your critical thinking to draw the conclusion of how this relates to wound healing.

This is a great question! I will give a short answer why, although I recommend looking into some published literature for a well-rounded understanding of this topic. Those who are diabetic but maintain a good A1C (ideally 6.5 or less, but 7 is also an acceptable standard) have less trouble with wound healing. Sugar crystals, when in excess, act as knives to the vessel walls, reducing blood flow. Less blood to the tissues means less oxygen, less oxygen means extending wound healing times. Also, with chronically poor controlled diabetes, calcification of the blood vessels occurs (hardening of the vessel), this can cause blood flow issues, and swelling. Those who have poorly controlled diabetes are also at higher risk for infection, since bacteria love sugar! When you have an open wound with bacteria on a person with diabetes, things can quickly go from a cut to an amputation! Hope this snippet helps. Also, there are many other articles I urge you to research regarding wounds and diabetes.

You need to go back to basic training and look up wound care for diabetics. Depending on this thread for your education is lazy on your part for not using a reliable resource for your question. Go to your med surg book and review it. Looking up these important questions will help you to become a better nurse. I wish you well.