Measuring sugar levels in blood and urine yourself

Photo of blood sugar measurement (PantherMedia / pasiphae) Many people with diabetes measure their blood sugar levels themselves. For those who inject insulin several times a day, checking their sugar levels with a blood glucose meter is an important part of their daily treatment.

If someone has diabetes, their blood sugar levels are checked regularly. In type 2 diabetes, once every few months is sometimes enough. But not if insulin injections are part of their treatment.This is because the amount of insulin that is injected at mealtimes depends on the measured blood sugar level, among other things. Sugar levels in blood or urine can be measured in various ways. It's also possible to measure the level of sugar in tissues of the body.

You can learn how to measure your blood sugar yourself in special patient education classes. These are a part of diabetes disease management programs (DMPs) too.

Measuring blood sugar levels yourself

You can measure your blood sugar levels yourself using an electronic device called a blood glucose meter. To do this, you prick your fingertip with a small needle, and place a drop of blood on a test strip. The strip is inserted into the blood glucose meter. Shortly after, your blood sugar level is displayed on the device's screen. More specifically, the procedure involves the following steps:

  • First of all, lay out everything you need. This includes a blood glucose meter, a blood-sampling device with a fine needle (lancet), and a test strip.
  • Wash your hands before measuring your blood sugar because dirt can distort the results.
  • Take a test strip out of the package and insert it into the glucose meter.
  • Gently prick the tip of a finger with the needle. It hurts less if you prick the side of the finger. Gently squeeze the tip of the finger until a small drop of blood comes out. It should just fill the test field on the strip.
  • Then carefully place the drop of blood on the test strip without smearing it.
  • After a short while your blood sugar level will be displayed on the meter. Modern devices can save the measurements along with the date and time, and this information can be transferred to a computer or smartphone. If this isn't possible, it's a good idea to write the measurements down in a special diary or app, for instance.

If you measure your blood sugar levels frequently, pricking yourself is less uncomfortable if you use a different finger – or a different place on your finger – each time.

It can be helpful to read up about the various available devices and how to use them properly before getting a new glucose meter. It must be easy to use in everyday life.

What does the reading mean?

It is completely normal for blood sugar levels to go up and down a little. This also happens in people who don't have diabetes. The amount of sugar in your blood is influenced by things like what you eat and drink, how much exercise you get, and what medications you take. Depending on whether blood sugar levels are measured on an empty stomach or immediately after a meal, they vary between 3.3 and 7.8 mmol/l (about 60 and 140 mg/dl) in people who don't have diabetes. There are no clear-cut boundaries between the normal range of blood sugar and high or low blood sugar.

Illustration: Blood sugar: Normal level between hyperglycemia and hypoglycemia, as described in the articleBlood sugar: Normal range between hyperglycemia and hypoglycemia

Measuring sugar in your urine yourself

You can also measure the blood sugar levels in your urine on your own. Having sugar in your urine is usually a sign of very high blood sugar levels. The extra sugar in the bloodstream is usually only removed via the kidneys at blood sugar concentrations of about 10 mmol/l (180 mg/dl) and above. In order to measure the amount of sugar in your urine, you need a urine test strip and a container for collecting urine.

It’s important to talk with your doctor about the best time of day to do the urine test, and whether to do it before or after eating. When measuring sugar in your urine yourself, you need a sample of urine that hasn’t been in your bladder for long. So you wouldn't use morning urine which has collected overnight. Instead, it’s more typical to urinate and collect a sample about an hour after the last time you went to the toilet. The test strip is then dipped into the sample. After about two minutes, the color pads on the test strip show the results.

What does the reading  mean?

To find out what the results mean, the colors on the test strip are compared with the color chart on the package. If the colors on the test strip don’t change, you don’t have sugar in your urine. The more the color changes, the more sugar there is in the urine, and therefore in the blood. But this urine test isn't suitable for seeing how effective treatment with medication is because it can't provide exact blood sugar readings. Urine tests only detect very high blood sugar. This is because the body doesn’t generally get rid of sugar in urine if someone’s blood sugar levels are normal or slightly high. If there is sugar in your urine, you should make an appointment to see a doctor about it.

Measuring blood sugar levels in a laboratory

Blood sugar levels can be measured a lot more accurately by taking a blood sample from a vein and having it tested in a laboratory. Blood sugar is sometimes measured as part of a routine blood test in hospital or at the doctor’s. A special kind of test called a glucose tolerance test involves taking blood samples to see how the body deals with larger amounts of sugar. You have to drink a liquid with a lot of sugar in it before the blood samples are taken.

Most people with diabetes have the HbA1c levels in their blood measured regularly. HbA1c is a measure of how high your blood sugar levels have been on average over the last two to three months This indicates how well controlled your blood sugar is and whether your diabetes treatment might need to be adjusted.

Additional measurement of sugar levels in body tissue

You can also monitor your sugar levels using a device that measures the amount of sugar in fat tissue underneath your skin. This is called continuous glucose monitoring (CGM). CGM devices measure the sugar levels in the tissue fluid (interstitial fluid) every few minutes, and alert you if your blood sugar is too high or too low. They are also available in combination with an insulin pump. But people with type 2 diabetes generally only use them if it isn’t possible to monitor their blood sugar properly using other approaches.