If I check my blood sugar before a meal and it is in the normal range, ( My doctor has me on a "sliding-scale" ) should I still give myself an injection of the Humalog insulin I am taking then or after I have finished eating and re-checking it an hour later?
That depends on what your sliding scale says. Usually, you still need to take insulin before a meal, even if your blood glucose is “normal,” as eating food will cause your blood glucose to rise. You need insulin to help keep your blood glucose from going too high and also to help bring your blood glucose down to a safe range 2-3 hours after you eat. Follow your sliding scale for insulin at mealtime and, on occasion, check your blood glucose 2-3 hours later. Your blood glucose should be within your target range (ask your doctor if you’re not sure what that is), and definitely under 180 mg/dl. If you’re glucose is higher than that, you may need more insulin at meal time, and/or you may need to count your carbohydrate more carefully at your meals. If you need help with carb counting, I’d suggest meeting with a dietitian for guidance.