You need to know how well you are taking care of your diabetes. You need to know if you are lowering your high blood sugar. The best way to find out is to test your blood to see how much sugar is in it. If your blood has too much or too little sugar in it, your doctor may need to change your eating, exercise, or medicine plan.
Some people test their blood once a day. Others test their blood three or four times a day. Your doctor may want you to test before eating, before bed, and sometimes in the middle of the night. Ask your doctor how often and when you should test your blood sugar.
How to Test Your Blood Sugar
To test your blood, you need a small needle called a lancet. You also need special blood testing strips that come in a bottle. Your doctor or diabetes educator will show you how to test your blood. Here are the basic steps to follow:
- Prick your finger with the lancet to get a drop of blood.
- Place the blood on the end of the strip.
- After a minute or so, the strip changes color. Match the color of the strip to a color chart on the bottle or box that the strips came in. This will give you a round number for your blood sugar, like 80 or 140.
- Put the strip into the meter. The meter will give you an exact number for your blood sugar, like 128.
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To get a more exact figure, you may want to use a blood sugar testing machine called a meter. If you use a meter, follow the first two steps listed above. Then:
Pricking your finger with a lancet may hurt a little. It's like sticking your finger with a pin. Use the lancet only once and be careful when you throw away used lancets. Ask your doctor or nurse how to throw them away safely.
You can buy lancets, strips, and meters at a drug store. Some of these items are costly, especially the blood testing strips. Lancets do not cost very much, and meters are often on sale. There are many different kinds of meters available in drug stores. If you decide to buy one, ask your doctor or diabetes educator for advice on what kind to buy. Take your blood testing items with you when you see your doctor or nurse so that you can learn how to use them correctly.
Other Tests For Your Diabetes
- Urine tests
You may need to test your urine ketones when you are sick or if your blood sugar is over 240 before eating a meal. A urine test will tell you if you have "ketones" in your urine. Your body makes ketones when there is not enough insulin in your blood. Ketones can make you very sick. Call your doctor right away if you find ketones when you do a urine test. You may have a sickness called "ketoacidosis." Ketoacidosis is serious. If not treated, it can cause death. Signs of ketoacidosis are vomiting, weakness, fast breathing, and a sweet smell on the breath. Ketoacidosis is more likely to develop in people with insulin-dependent diabetes.
You can buy strips for testing urine ketones at a drug store. Your doctor or diabetes educator will show you how to use them.
- The hemoglobin Alc Test
Another test for blood sugar, the hemoglobin A1c test, shows what your average blood sugar was for the past 3 months. It shows how much sugar is sticking to your red blood cells. The doctor does this test to see what level your blood sugar is most of the time.
See your doctor for a hemoglobin A1c test every 3 months. To do the test, the doctor or nurse takes a sample of your blood. The blood is tested in a laboratory. The laboratory sends the results to your doctor.
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If most of the blood sugar tests you do yourself show that your blood sugar is around 150, the hemoglobin A1c test should be almost normal. If most of your tests show high levels of blood sugar, then the hemoglobin Alc test is usually high. Ask your doctor what your hemoglobin A1c test showed.
NIDDK