What sample is required?
The determination is made from a venous blood sample, or for personal control, a drop obtained from the finger by puncture with a lancet; sometimes a random urine sample is needed. Some diabetics use a continuous monitor that consists of a small sensor placed under the skin of the abdomen and that allows glucose levels to be monitored every five minutes.
Is some kind of prior preparation necessary?
It is usually recommended to fast - refrain from drinking or eating except water - from 8 hours before performing a blood glucose test. In diabetic people, glucose levels can be monitored fasting and after meals to finally achieve better control of the disease. The doctor will take care of providing the appropriate instructions.