Low blood sugar (hypoglycemia) means that the level of
sugar (glucose) in your blood has dropped below what your body needs to
function normally. When your blood sugar level drops below 70
milligrams per deciliter (mg/dL), you will usually
have symptoms of low blood sugar, which can develop
If your blood sugar level drops just slightly below your
target level (mild low blood sugar), you may feel
tired, anxious, weak, shaky, or sweaty, and you may have a rapid heart rate. If
you eat something that contains sugar, these symptoms may last only a short
time. If you have had diabetes for many years, you may not always notice
symptoms of mild low blood sugar. This is called hypoglycemia unawareness. If
your blood sugar is well-controlled and does not change much during the day,
you may be at risk for hypoglycemia unawareness.
If your blood
sugar level continues to drop (usually below 40 mg/dL), your behavior may
change, and you may feel more irritable. You may become too weak or confused to
eat something to raise your blood sugar level.
If your blood sugar
level drops very low (usually below 20 mg/dL), you may
lose consciousness or have a
seizure. If you have symptoms of severe low blood
sugar, you need medical care immediately.
Check your blood sugar level often after you have taken steps
to raise it to make sure your level returns to and remains normal. A low blood
sugar level may soon recur, even though it has been treated. For example, the
long-acting insulin can continue to reduce blood sugar levels for up to 36
hours after an episode of low blood sugar.
Home blood sugar testing will help you identify a low
blood sugar level.
If your episodes of low blood sugar levels are
occurring more frequently, a visit to your doctor is needed.
How this information was developed to help you make better health decisions.