How to Monitor Blood Glucose

How to Help Your Loved One Monitor Blood Glucose

Why should someone with type 2 diabetes montitor her blood glucose?

If someone with type 2 diabetes controls her blood glucose, she's more likely to feel her best, stay healthy, and prevent or delay diabetes complications. To keep within her target range she'll need to monitor her blood sugar on a regular basis.

Over the past few decades, self-monitoring devices have transformed diabetes self-care. Results are instantaneous, and the information helps you and the person you're caring for figure out whether she needs to change her diet, get more exercise, or ask the doctor whether her medications need adjusting. A high or low reading alerts you and her to potential problems as well.

1. How does she monitor it?

Self-monitoring of blood glucose requires a portable glucose meter, a small, battery-operated device. It's used to check blood sugar on a regular basis in order to maintain levels that are as close to normal as possible.

2. Why should she check her blood glucose?

In the long term, keeping blood glucose under control -- ideally between 90 and 130 milligrams per deciliter (mg/dl) before a meal and under 180 mg/dl after a meal -- can help her prevent or delay diabetes complications, such as nerve, eye, kidney, heart, and blood vessel damage. In the short term, maintaining glucose levels in her target range can help her stave off problems such as hypoglycemia (low blood sugar) and hyperglycemia (high blood sugar).

Testing regularly and recording the results helps the person you're caring for and the members of her healthcare team get a good sense of her body's response to her diabetes treatment plan, helps uncover trends that reveal which drugs, exercise regimens, and diet work and which don't, and lets her know how her body is affected by food, activity, stress, medications, and other variables.

Regular testing is the only way to know if her blood glucose level is within her recommended range. This information can help her make day-to-day decisions about managing her blood sugar and alert her to potential emergency situations. In short: The tighter her glucose control, the healthier she's likely to be.

3. How does she check her blood sugar?

  • Getting a blood sample To test for glucose in the blood with a typical glucose meter -- a small digital machine that measures the amount of glucose in someone with diabetes's blood -- a small sample of blood is taken from her fingertip via a pen-style, spring-loaded tube into which she puts a needle, known as a lancet. A dial on the lancet allows her to choose how deeply the needle enters her skin.
  • Using the test strip Before using the lancet the person you're caring for should wash her hands with soap and dry them. To avoid sore spots on the pads of her fingers, she should stick the side of her fingertip by her fingernail. The blood drop is then placed on a disposable test strip. With most meters, this strip slides into the glucose meter before the blood is applied to a specific area on the strip, which is coated with chemicals that combine with the glucose in the blood sample. The meter displays the glucose level as a number on a screen. Obtaining a reading typically takes less than a minute.
  • Keeping a log She should then make a note of this number in her blood sugar log. Although many meters store the results, it's still a good idea to keep a written record to look for patterns.
  • Learning to use the meter Not all meters work the same way. So it's important for you and the person you're caring for to learn how to use her glucose-monitoring device correctly and, equally important, how to interpret its results. Both of you also need to know how to calibrate the meter or set it correctly for each new batch of test strips she uses. You and she should get training from a certified diabetes educator, who will watch you both test for glucose and calibrate the meter to make sure you're using the equipment correctly. Be sure to read the manufacturers' instructions as well.
  • Solving problems Keep the user manual in a handy place to help solve any problems that may arise. Many meters, for instance, display error codes when there's a problem with the meter, test strip, or blood sample. You may need to refer to the manual to interpret these codes to remedy the situation. Further information on her meter should be available through the toll-free manufacturer number or from her primary healthcare provider, diabetes educator, or local emergency room. Meter manufacturers usually have a website, which is also a good place to check to see if any issues with the function of the meter have arisen.
  • Buying supplies Testing strips and lancets are available via prescription. Meters can be found at pharmacies or online by searching for blood glucose monitor, or her healthcare provider may give her one.
  • Using other devices Less commonly, continuous glucose monitoring is possible through a watch-like device worn on the wrist or a sensor that's continuously worn on the abdomen connected to a catheter under the person's skin. These devices don't replace finger-prick tests; they're used to obtain additional glucose measurements between regular testing.

Glucose-monitoring equipment for someone with type 2 diabetes

4. What should I consider when helping someone with diabetes choose glucose-monitoring equipment?

A primary healthcare provider, diabetes educator, or pharmacist can help you select equipment that's right for her. Some things to consider: Fine-gauge needles for lancets are available for fragile skin. Some devices combine a blood glucose meter with a lancing device; the convenience of such a gadget may appeal to her.

Over two dozen meters are available, and they differ in several ways, including size, speed, cost of the meter, cost of the test strips used, amount of blood needed, and ability to store test results. Some meters are very compact; if she has dexterity problems, she may find a larger one more helpful. Likewise, meters with bigger result displays may be easier to read if eyesight is an issue. Some meters have a large memory, which could be useful if she forgets to jot down test results. Some models connect to computers to store or print test results; check with her doctor to see if it would be useful for her to get her test results this way.

Some meters allow users to add blood if getting an adequate sample the first time is a challenge. In addition, some allow the person to take blood from places other than the fingertip, which is the usual pricking point for a blood sample. This is known as alternative site testing and may involve getting a sample from the palm, forearm, or abdomen.

5. What factors can affect glucose meter accuracy?

The reliability of glucose meter test results depends, in part, on the quality of the person's meter and test strips, as well as her ability to use the equipment correctly, which is why training on the device is important. Always check expiration dates on blood testing strips before use. Other factors that can cause unpredictable or unreliable test results include altitude, temperature, and humidity, as well as other substances -- from vitamin C to glucose tablet residue to uric acid (a natural body chemical that tends to be more concentrated in people with diabetes) to hematocrit (the amount of red blood cells in the blood).

6. How often should someone with type 2 diabetes test herself?

Frequent monitoring offers her the best chance at keeping her blood sugar in her target range. Her healthcare provider will make a recommendation on how often she should test based on a number of factors, including the medications she takes and how often she experiences symptoms that her blood sugar is too high or too low. It's recommended that people with type 2 diabetes check before meals, two hours after meals, at bedtime, and first thing in the morning. Testing just once or twice a day is better than not testing at all. Of course, she should test any time she experience diabetes symptoms, and she should check more often if she changes medications, feels ill, is under greater stress, or experiences any other out-of-the-ordinary circumstances.

7. How do we check the accuracy of glucose monitoring equipment?

It's wise to perform quality control checks about once a month. Meters that have been dropped may malfunction, for instance, batteries or electrical components may have worn out, or humidity or heat may damage test strips.

  • Control solutions Manufacturers generally offer two kinds of quality control checks: Test quality control solutions allow you to check the reliability of the meter and strip and may also give some indication of how well you or she use the system by substituting a test solution -- with a predictable result that's known to you -- for a blood sample. Some manufacturers include quality control solution with their meters; if not, order it from the manufacturer or her pharmacist. The solution typically expires within a month, so check the "use by" dates.
  • Electronic controls Alternatively, some meters use electronic controls to make sure the device is working properly. This method requires that a cartridge or special "control" test strip be inserted into the meter; a signal will appear if the meter is working correctly.

It's a good idea for you or the person you're caring for to bring her glucose meter along on routine visits to her healthcare provider, who can watch her technique to make sure she's using the meter properly.

Her provider will also take a blood sample and have it evaluated in a lab to make sure the self-management measure matches the lab test results.

8. What should she do with the results?

If her blood sugar readings are routinely above or below her target range, then she should consult with her main diabetes healthcare provider, as she may need to revise her treatment plan. These numbers could be a sign that complications are brewing, that she's not following her treatment plan, or that the plan needs adjusting. Equally important, if she regularly meets her blood sugar goals, she should take comfort in knowing she's on track to maintain her health.

Sarah Henry

Sarah Henry has covered health stories for most of her more than two decades as a writer, from her ten-year stint at the award-winning Center for Investigative Reporting to her staff writer position with Hippocrates magazine to her most recent Web work for online sites, including WebMD, Babycenter. See full bio