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When Your Blood Sugar Is Too High or Too Low

Sometimes, no matter how hard you try to keep your blood sugar in the range your doctor has advised, it can be too high or too low. Blood sugar that is too high or too low can make you very sick. Here's how to handle these emergencies.

What You Need to Know about High Blood Sugar

If your blood sugar stays over 240, it is too high. High blood sugar usually comes on slowly. It happens when you don't have enough insulin in your body. High blood sugar can happen if you miss taking your diabetes medicine, eat too much, or don't get enough exercise. Sometimes, medicines you take for other problems may cause high blood sugar. Be sure to tell your doctor about other medicines you take.

This chart shows the ranges of blood sugar.

Having an infection or being sick or under stress can also make your blood sugar too high. That is why it is very important to test your blood and keep taking your medicine (insulin or diabetes pills) when you have an infection or are sick.

Your blood sugar may be too high if you are very thirsty and tired, have blurry vision, are losing weight fast, and have to go to the bathroom often. Very high blood sugar may make you feel sick to your stomach, faint, or throw up. It can cause you to lose too much fluid from your body.

Testing your blood sugar often, especially when you are sick, will warn you that your blood sugar may be rising too high. If your blood sugar stays over 300 when you check it two times in a row, call your doctor. You may need a change in your insulin shots or diabetes pills, or a change in your meal plan.

If you are not sick and do not have ketones in your urine, going for a slow walk or some other easy exercise may lower your blood sugar.

What You Need to Know about Low Blood Sugar

If your blood sugar drops too low, you can have a low blood sugar reaction, called hypoglycemia. A low blood sugar reaction can come on fast. It is caused by taking too much insulin, missing a meal, delaying a meal, exercising too much, or drinking too much alcohol. Sometimes, medicines you take for other health problems can cause blood sugar to drop.

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