Shield Medical Group

How to Check Blood Sugar Properly: Best Times, Target Numbers, CGM vs Fingerstick, and Common Mistakes
Dr. Kulmeet Kundlas explains how to properly monitor type 2 diabetes by understanding what blood sugar readings mean, when to check them, and common pitfalls. He compares home fingerstick testing, continuous glucose monitors (CGMs) with a 10–15 minute lag and possible compression errors, hemoglobin A1C as a 3–4 month lagging indicator that hides extremes, and ketone testing (especially for type 1 and SGLT2 inhibitor users). Key targets include fasting/pre-meal 80–130 and 2-hour post-meal (timed from the first bite) ≤180, with bedtime checks particularly important for patients on insulin or sulfonylureas to avoid nocturnal hypoglycemia and the Somogyi effect. He outlines individualized A1C goals, symptoms of hypo/hyperglycemia and DKA, when to call a doctor vs go to the ER, the rule of 15 for low sugar, and proper fingerstick technique and strip storage.