Dealing with low blood sugar from medications for type 2 diabetes
What is a low blood sugar (hypoglycemia) emergency?
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 3.6 millimoles per litre (mmol/L), you most likely will have symptoms, such as feeling tired, weak, or shaky. Symptoms of low blood sugar usually develop quickly.
- If your blood sugar level drops just slightly below a safe range, you may have symptoms of mild low blood sugar. If you eat something that contains sugar, they may last only a short time. If you have had diabetes for many years, you may not realize your blood sugar is low until it drops very low. This is called hypoglycemia unawareness.
- If your blood sugar level continues to drop (usually below 2.2 mmol/L), your behaviour may change. Symptoms of moderate low blood sugar may develop. You may become too weak or confused to eat something to raise your blood sugar level.
- If your blood sugar level drops very low (below 1.1 mmol/L), you may lose consciousness or have a seizure. If you have symptoms of severe low blood sugar, you need medical care immediately.
What causes low blood sugar?
Some oral medications used to treat diabetes as well as insulin shots can cause low blood sugar levels. This is more likely to happen if you eat less food than usual, exercise, or do intense physical work. Very low blood sugar levels most often develop rapidly (in 10 to 15 minutes) when a person has skipped a meal and is doing intense physical work. Reduced kidney function can prolong the action of diabetes medication, possibly making low blood sugar levels more frequent.
Usually, blood sugar levels in people who take diabetes medication drop only low enough to cause mild symptoms. Very low blood sugar levels usually do not occur in people with diabetes who do not take insulin shots. Some pills used to treat type 2 diabetes are more likely to cause low blood sugar than others.
Low blood sugar levels can occur if you:
- Take too many of your sulfonylurea pills in a day or take your doses too close together.
- Continue to take your full dose of sulfonylurea pills when you are not going to eat your usual amount of food.
- Exercise strenuously without eating enough food.
- Drink too much alcohol, especially on an empty stomach.
- Take certain other medications that lower blood sugar. Some medications that you can buy without a prescription can affect blood sugar. Talk with your health professional about your prescription and non-prescription medications and the risk of developing very low blood sugar levels.
Test Your Knowledge
Low blood sugar means that the level of sugar in the blood has dropped below what the body needs to function normally—usually below 3.6 mmol/L.
Very low blood sugar levels (below 1.1 mmol/L) are emergency situations and require immediate care.
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Why do I need to deal with low blood sugar emergencies?
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| Author: | Merrill Hayden Carrie Henley | Last Updated: April 28, 2006 |
| Medical Review: | Adam Husney, MD - Family Medicine Caroline S. Rhoads, MD - Internal Medicine Hanan Bassyouni, MD - Endocrinology and Metabolism Matthew I. Kim, MD - Endocrinology & Metabolism David C.W. Lau, MD, PhD, FRCPC - Endocrinology & Metabolism Jill Milliken, RN, CDE - Diabetes Educator | |
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