Type 1 diabetics usually check blood sugar levels three or more times per day, including before and after meals, before and after exercise and before bed. Type 2 diabetics typically perform blood tests before meals, after fasting at least eight hours and sometimes after meals, according to Mayo Clinic.
How many times someone checks blood glucose levels is up to a doctor, and frequency of testing depends on the type of diabetes and the treatment plan. Type 1 diabetics may also test blood sugar when they are ill, change their daily routine or begin new medicines, notes Mayo Clinic. Type 1 diabetics may also test blood glucose levels at night. Type 2 diabetics test blood sugar levels based on how many doses of insulin they take during the day. Some type 2 patients who manage diabetes without insulin may not need to test glucose levels daily.
Diabetics should write down their blood sugar levels and review the results to determine how eating, stress and physical activity affects glucose levels. Patients can see if high or low levels occur at a particular time of day, which may indicate a treatment plan needs to be changed, according to the American Diabetes Association. Blood glucose targets for individuals are based on someone's age, duration of diabetes, cardiovascular disease complications, hypoglycemia and individual patient considerations. Normal levels before a meal range from 70 to 130 milligrams per deciliter, and post-meal glucose levels should be below 180 milligrams per deciliter.