Blood Testing Basics

A handout by the Stanford University Medical Center

Why Should I Test ?

Testing your blood sugar regularly can help you know how well your diabetes is being controlled. By minimizing your high and low blood sugars, you feel better and stay healthier.  Regular testingwill help you and your diabetes care team determine if your treatment plan is working.

When Should I Test ?

Most people with diabetes test their blood glucose everyday in the morning before breakfast.  Some people also test before lunch, dinner and bedtime.  You can test two hours after a meal to see the effect of your meal on your blood glucose.  Many people test before and after exercise to make sure their blood glucose doesn’t go too low.  How often you test also depends on: 1) whether or not your diabetes is under control, 2) the amount and type of medication you take, and 3) how much testing you’re willing to do.  Discuss how often you should test with your physician.

What Supplies Do I need to Perform a Blood Test ?

  • Blood Glucose Meter
  • Lancet Device
  • Test Strips
  • A Kleenex or Cotton Ball
  • A Place to Wash your Hands
  • Blood Sugar Testing Diary

How to Check your Blood Glucose

  • Wash your Hands with warm water and soap.  Rinse and dry completely.
  • Prepare the Meter:  Follow the directions in your meter instruction book.
  • Prick your Finger with the Lancet. Before you stick yourself, let your arm hang down at your side to improve blood flow. Prick your finger and squeeze or “milk” it until you get a drop of blood.
  • Place the Blood on the Test Strip.
  • Follow your meter’s directions about how large the blood sample should be and how to place the blood sample on the test strip.
  • Read and Record the Meter Results in your Logbook.
  • Note the result, date, time and any other comments in your logbook.
  • Always bring your logbook with you when you see your diabetes care team.

For meter problems: Call the company’s toll-free information number on the back of your meter.

What Should My Blood Sugar Goals Be?

The recommended goals shown below are the values that help most people feel good everyday and protect against the development of the long-term complications of diabetes.  These general guidelines may need to be individually adjusted, so work with your health care team to develop goals which are right for you.  For most people, the goal is to have “near-normal” control.  Check if the meter you use reports results as “whole blood glucose” or as “plasma glucose”.  Most meters test whole blood glucose, however, many meters convert the result to a plasma value so that it can be compared to a plasma glucose drawn in a laboratory.  Refer to your meter’s instruction book or the company hotline for further information.


Whole Blood Glucose  Plasma Blood Glucose
Fasting
Before Meals
Bedtime 		80  – 120
80  – 120
100 – 140		 90 –  130
90 –  130
110 – 150

           

What is Control Solution?

• Every meter has a control solution that is used to check whether your meter and strips are working together as a system and that you are doing the test correctly.  Before you use your meter for the first time, follow your meter’s instructions on control solution testing.
• Every time you open a new vial or package of strips, you should perform a quality test with control solution.
• Compare the results of your control test to the range listed on your bottle of strips or on the package insert.
• Unopened control solution is good until the expiration date.  Once opened, control solution may only be used for 3-4 months.  Refer to the package insert.

How Can I Prevent Sore Fingers?

• Choose a different spot on the side of your fingers each time you test. Repeated punctures in the same spot can make your finger sore and callused.  Try to use both sides of each finger and rotate to all your fingers.
• If you find that sore fingers are preventing you from testing as often as you should, try the new ultra fine lancets and penlets that allow you to adjust the depth of the lancet penetration, or ask your diabetes educator for help.
• There are new meters available that allow blood testing in other areas besides the fingers such as the palm, lower arm or upper thigh.  If you are interested in one of these meters, ask your diabetes educator or contact Lifescan (800-227-8862), Bayer (800-348-8100), Medisense (866-763-8228) or Therasense (888-522-5226).