When first diagnosed with diabetes , many people hear the words blood glucose testing for the first time. This blood glucose guide discusses testing your blood glucose, when you should test your blood sugar, and how often you should to this. Once you have a blood glucose meter and test strips , and you know the blood glucose testing routine, when should you test? How often do you need to test? How important is testing for good diabetes care?
How often you test will depend partly on your experience, your diabetes type , and your diabetes treatment regime. How the body responds to meals is likely to be an issue for all people with diabetes. Where possible, it is well advised to test before and after certain meals to see how your sugar levels respond. Blood testing more often when ill is also recommended as illness can often cause blood glucose levels to fluctuate. If your medication may cause hypoglycemia, you should test before undertaking tasks for which hypos would pose a danger to you or others, such as:
- Before driving
- Strenuous activity or
- Using powered tools
Treated by diet
People with diabetes treated by diet, oral medication or by once or twice daily injections (such as Byetta, Victoza ) may not need to test every day either but would be advised to test before and after certain meals and particularly if their levels are running outside of the recommended blood glucose level ranges
Long acting insulin
People on long acting insulin alone may not need to test every day but would be advised to test on a fairly regular basis to ensure blood sugar is not creeping too high or low at different times of the day or after particular meals and activities.
Shorter acting insulin
People on shorter acting insulins should test their blood glucose on a regular basis. Insulin dependent diabetics will fairly typically test anywhere between 2 to 8 times a day. Unless blood sugar levels are particularly stable (this can happen shortly after being diagnosed in people with type 1 diabetes), it is advisable to test at least twice a day. Insulin can cause hypoglycemia during the night so some people may wish to test either side of sleeping as well.
Get into a routine
People with diabetes need to pay particular attention to daily routines that other people without diabetes might take for granted. For instance, heading to the gym, eating a pub lunch, having an alcoholic drink or missing mealtimes might not concern a person without diabetes but they all have an impact on blood sugar levels.
Awareness
Being aware of high and low blood glucose levels , and the seemingly small events that effect blood glucose, is an essential part of good diabetes management. Keeping your blood glucose under control can reduce the future burden of diabetes complications and the risk of hypoglycemia or hyperglycemia Blood glucose testing is a way of keeping in touch with your diabetes. Blood glucose testing can also be useful for healthcare professionals By checking average results, doctors and nurses can find out whether you are in control and advise you accordingly. They can also track the effects of your treatment and make adjustments to your treatment to seek better blood glucose control.
Diabetes - home glucose testing; Diabetes - home blood sugar testing Checking your blood sugar levels often and recording the results will tell you
how well you are managing your diabetes so you can stay as healthy as possible. The best times to check your blood sugar are before meals and at bedtime. Your blood sugar meter may have software to help you track your blood sugar level. This is usually available from the manufacturer's website.
Check Your Blood Sugar Often
Not everyone with diabetes needs to check their blood sugar every day. Others need to check it many times a day.
Usual times to test your blood sugar are before meals and at bedtime. Your provider may ask you to check your blood sugar 2 hours after a meal or even sometimes in the middle of the night. Ask your provider when you should check your blood sugar.
Other times to check your blood sugar may be:
- If you are having symptoms of low blood sugar (hypoglycemia)
- After you eat out, particularly if you have eaten foods you don't normally eat
- If you feel sick
- Before or after you exercise
- If you have been under a lot of stress
- If you eat too much or skip meals or snacks
- If you are taking new medicines, took too much insulin or diabetes medicine by mistake, or took your medicine at the wrong time
- If your blood sugar has been higher or lower than normal
- If you are drinking alcohol
How to Prepare for the Test
Have all test items within reach before starting. Timing is important. Clean the needle prick area with soap and water. Completely dry the skin before pricking. Do not use an alcohol pad or swab to clean the skin. Alcohol is not effective in removing sugar residue from the skin.
How the Test is Done
You can buy a testing kit from a pharmacy without a prescription. Your provider can help you choose the right kit, set up the meter, and teach you how to use it.
Most kits have:
- Test strips
- Small needles (lancets) that fit into a spring-loaded plastic device
- A logbook for recording your numbers that can be downloaded and viewed at home or at your provider's office
To do the test, prick your finger with the needle and place a drop of blood on a special strip. This strip measures how much glucose is in your blood. Some monitors use blood from areas of the body other than the fingers, reducing discomfort. The meter shows your blood sugar results as a number on a digital display. If your vision is poor, talking glucose meters are available so that you don't have to read the numbers.
Be aware that no meter or strip is accurate 100% of the time. If your blood sugar value is unexpectedly high or low, measure again with a new strip. Do not use strips if the container has been left open or if the strip has gotten wet.
Keep a Record
Keep a record for yourself and your provider. This will be a big help if you are having problems controlling your diabetes. It will also tell you what you did when you were able to control your diabetes. To get the most help with controlling your blood sugar, write down:
- The time of day
- Your blood sugar level
- The amount of carbohydrates you ate
- The type and dose of your diabetes medicine
- The type of any exercise you do and how long you exercise for
- Anything unusual, such as stress, eating different foods, or being sick
Blood sugar meters can store hundreds of readings. Most types of meters can save readings to your computer or smart phone. This makes it easy to look back at your record and see where you may have had problems. Often the pattern of blood sugar changes from one time to another (for example, from bedtime to morning time). Knowing this is helpful for your provider.
Always bring your meter when you visit your provider. You and your provider can look at your blood sugar patterns together and make adjustments to your medicines, if needed.
You and your provider should set a target goal for your blood sugar level for different times of the day. If your blood sugar is higher than your goals for 3 straight days and you don't know why, call your provider.
References
American Diabetes Association Professional Practice Committee. 5. Facilitating behavior change and well-being to improve health outcomes: Standards of Medical Care in Diabetes-2022. Diabetes Care. 2022 Jan 1;45(Suppl 1):S60-S82. PMID: 34964866. pubmed.ncbi.nlm.nih.gov/34964866/.
American Diabetes Association Professional Practice Committee. 6. Glycemic targets: Standards of medical care in diabetes-2022. Diabetes Care. 2022 Jan 1;45(Suppl 1):S83-S96. PMID: 34964868. pubmed.ncbi.nlm.nih.gov/34964868/.
Atkinson MA, Mcgill DE, Dassau E, Laffel L. Type 1 diabetes. In: Melmed S, Auchus, RJ, Goldfine AB, Koenig RJ, Rosen CJ , eds. Williams Textbook of Endocrinology. 14th ed. Philadelphia, PA: Elsevier; 2020:chap 36.
Riddle MC, Ahmann AJ. Therapeutics of type 2 diabetes. In: Melmed S, Auchus, RJ, Goldfine AB, Koenig RJ, Rosen CJ , eds. Williams Textbook of Endocrinology. 14th ed. Philadelphia, PA: Elsevier; 2020:chap 35.
Version Info
Last reviewed on: 2/1/2022
Reviewed by: Sandeep K. Dhaliwal, MD, board-certified in Diabetes, Endocrinology, and Metabolism, Springfield, VA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.