By Martha Funnell, MS, RN, CDE

One of the most frustrating things about caring for diabetes is when your blood glucose readings go up and  down for no apparent reason. You work hard to stick with your routine from day to day, but your blood glucose seems to have a mind of its own. The following information may give you clues to help you figure out the reasons behind your up and down readings.

What raises your blood glucose level?

Most people think of sugar as the main culprit, but all carbohydrates can raise your blood glucose. Carbohydrates are found in fruits, vegetables, starches and sugars. Fat and proteins do not have any direct effect on your blood glucose and can actually slow down how quickly your glucose level goes up after you eat carbohydrates. Carbohydrate foods that are high in fiber can also have less of an effect on your blood glucose. So, even though you eat the same amount of carbohydrates, the amount of fiber, fat or protein you eat at the same time can affect your results.

What lowers your blood glucose level?

Medicines to treat diabetes—pills, insulin and other injectables— work to lower your blood glucose. Physical activity also lowers your blood glucose level. However, physical activity is more than going to the gym or even walking. Housework, yard work or even a day walking around the mall can lower your blood glucose numbers. Alcohol also can lower your blood glucose.

What can raise or lower blood gluscose?

Certain medicines (including over-the-counter and herbal products) can either raise or lower your blood glucose levels. Some people find that stress, especially over an extended period of time, raises their blood glucose, but others find that stressful events lower their levels. Some women have higher or lower readings at different times during their menstrual cycle.

How to get started

Start with your fasting blood glucose reading. Your blood glucose level when you get up should be about the same as the reading before you go to bed, unless you eat additional carbohydrates. If your reading is higher, you may need an increase in your dose of evening medication or a different type of medication. If it is lower, you may need a decrease in your dose.

Talk with your health care team

Your health care provider can be a helpful partner in your detective work, but your team can be most helpful if you give them all the clues. Instead of just saying, “My blood glucose is all over the place,” show them your record, let them know what you have tried, how it worked and what you have figured out about your readings. After all, no one knows your body and your diabetes better than you do.

Using the clues

Just like a good detective, you need to be able to use clues to solve the mystery of your blood glucose readings. The following strategies can help you examine and understand your readings: