Low blood sugar (hypoglycemia) can affect people who have diabetes. It occurs when there's too much insulin and not enough sugar (glucose) in your blood. Hypoglycemia is defined as blood sugar below 70 milligrams per deciliter (mg/dL) or 4 millimoles per liter (mmol/L). Several factors can cause hypoglycemia in people with diabetes, including taking too much insulin or other diabetes medications, skipping a meal, or exercising harder than usual.
Pay attention to early warning signs, so you can treat low blood sugar promptly. Treatment involves short-term steps — such as taking glucose tablets — to raise your blood sugar into a normal range.
Left untreated, diabetic hypoglycemia can lead to seizures and loss of consciousness. This is considered a medical emergency. Tell family and friends what symptoms to look for and what to do in case you're not able to treat diabetic hypoglycemia yourself.
Early warning signs and symptoms
Early signs and symptoms of diabetic hypoglycemia include:
Irritability or moodiness
Anxiety or nervousness
Diabetic hypoglycemia can also occur while you sleep. Signs and symptoms include:
Damp sheets or bed clothes due to perspiration
Tiredness, irritability or confusion upon waking
If early symptoms of diabetic hypoglycemia go untreated, signs and symptoms of severe hypoglycemia can occur. These include:
Clumsiness or jerky movements
Difficulty speaking or slurred speech
Blurry or double vision
Convulsions or seizures
Take your symptoms seriously. Diabetic hypoglycemia can increase the risk of serious — even deadly — accidents. Identifying and correcting the factors contributing to hypoglycemia, such as medications you take or irregular meal times, can prevent serious complications.
Informing people you trust, such as family, friends and co-workers, about hypoglycemia is important. Their knowledge of what symptoms to look for and what to do in case you're not able to treat hypoglycemia yourself can make a potentially difficult situation easier to manage.
Not everyone has the same symptoms or the same symptoms each time, so it's important to monitor your blood sugar levels regularly and keep track of how you're feeling when you do have low blood sugar. Some people don't experience any early symptoms. This is called hypoglycemia unawareness.
When to see a doctor
Hypoglycemia can leave you confused or even unconscious, which requires emergency care. Make sure your family, friends and co-workers know what to do.
If you lose consciousness or can't swallow:
You shouldn't be given fluids or food which could cause choking.
You need an injection of glucagon — a hormone that stimulates the release of sugar into the blood.
You need emergency treatment in a hospital if a glucagon injection isn't on hand.
If you experience symptoms of hypoglycemia several times a week, see your doctor. You may need to change your medication dosage, change the type of medication you take or make other adjustments to your diabetes treatment program.
Hypoglycemia is most common among people who take insulin, but it can also occur if you're taking oral diabetes medications.
Common causes of diabetic hypoglycemia include:
Taking too much insulin or diabetes medication
Not eating enough
Postponing or skipping a meal or snack
Increasing exercise or physical activity without eating more or adjusting your medications
Blood sugar regulation
Glucose levels in the blood are controlled through a complex interaction of hormones that vary depending on whether you're fasting or have eaten. Insulin is the hormone responsible for lowering glucose levels when glucose is elevated. If you have type 1 or type 2 diabetes and need insulin to control your blood sugar, taking more insulin than you need can cause your blood sugar level to drop too low and result in hypoglycemia.
Hypoglycemia also may result if, after taking your diabetes medication, you eat less than usual or exercise more than you normally do. Your doctor can work with you to prevent this imbalance by finding the dose that fits your regular eating and activity patterns.
If you ignore the symptoms of hypoglycemia too long, you may lose consciousness. That's because your brain needs glucose to function. Recognize the signs and symptoms of hypoglycemia early because untreated, hypoglycemia can lead to:
Loss of consciousness
On the other hand, be careful not to overtreat your low blood sugar. If you do, you may cause your blood sugar level to rise too high (hyperglycemia). This, too, can be dangerous and eventually may damage your nerves, blood vessels and various organs.
Following are suggestions that can help prevent diabetic hypoglycemia:
Don't skip or delay meals or snacks. If you take insulin or oral diabetes medication, it's important that you be consistent about the amount and timing of your meals and snacks. The food you eat must be in balance with the insulin working in your body.
Monitor your blood sugar. Depending on your treatment plan, you may check and record your blood sugar level several times a week or several times a day. Careful monitoring is the only way to make sure that your blood sugar level remains within your target range.
Measure medication carefully, and take it on time. Take your medication as recommended by your health care provider.
Adjust your medication or eat additional snacks if you increase your physical activity. The adjustment depends on the blood sugar test results and on the type and length of the activity.
Eat a meal or snack with alcohol, if you choose to drink. Drinking alcohol on an empty stomach can cause hypoglycemia.
Keep a record of any low glucose reactions. This can help you and your health care team see patterns contributing to hypoglycemia and find ways to prevent them.
Carry some form of diabetes identification so in an emergency others will know that you have diabetes. Use a medical identification necklace or bracelet and wallet card.
If you experience symptoms of hypoglycemia several times a week, schedule an appointment with your doctor. Together you can determine what factors may be contributing to the hypoglycemia and decide what changes to make to prevent future episodes of low blood sugar.
It's a good idea to prepare for your appointment. Here's some information to help you get ready for your appointment, and to know what to expect from your doctor.
What you can do
Be aware of any pre-appointment restrictions. If your doctor is going to test your blood sugar, he or she will ask you to refrain from eating or drinking anything but water for eight hours for a fasting glucose test or four hours for a pre-meal test. When you're making an appointment, ask if fasting is necessary.
Write down your symptoms and how often they occur. It may help to keep a record of any low blood sugar reactions so you and your doctor can see patterns leading to hypoglycemia and find ways to prevent them.
Write down key personal information, including any major stresses or recent life changes. If you're monitoring your glucose values at home, bring a record of the glucose results, detailing the dates and times of testing.
Make a list of all medications, vitamins and supplements you take.
Create a record of metered glucose values. Give your doctor a written or printed record of your blood glucose values, times and medication. Using the record, your doctor can recognize trends and offer advice on how to prevent hypoglycemia.
Take your glucose meter with you. Some meters download recorded glucose values, which often can be done at your doctor's office.
Write down questions to ask your doctor. Be clear about aspects of your diabetes management that you need clarification on.
Be aware if you need any prescription refills. Your doctor can renew your prescriptions while you're there.
For diabetic hypoglycemia, questions you may want to ask include:
How often do I need to monitor my blood sugar?
What is my goal range?
How do diet, exercise and weight changes affect my blood sugar?
How can I prevent low blood sugar?
Do I need to worry about high blood sugar? What are the signs and symptoms I need to watch out for?
Do I need a prescription for the emergency injection of glucagon?
What kind of follow-up, if any, should I expect?
Don't hesitate to ask any other questions.
What to expect from your doctor
Your doctor is likely to ask you a number of questions, such as:
What symptoms do you notice when you have low blood sugar?
How often do you experience these symptoms?
What steps do you take to raise your blood sugar levels?
How often do you test your blood sugar?
What medications are you taking, and how often?
What's a typical day's diet like?
Are you exercising? If so, how often?
Do your family, friends and co-workers know what to do if you experience severe hypoglycemia?
You can determine if you have low blood sugar by using a blood glucose meter — a small computerized device that measures and displays your blood sugar level. You have hypoglycemia when your blood sugar level drops below 70 milligrams per deciliter (mg/dL) or 4 millimoles per liter (mmol/L).
It's important to record the date, time, test results, medication and dosage, and diet and exercise information each time you test your blood. Also, note any low blood sugar reactions. Your doctor diagnoses hypoglycemia using your records and looks for patterns to see how your medications and lifestyle affect your blood sugar.
If you think that your blood sugar may be dipping too low, check your blood sugar level with a blood glucose meter. Then eat or drink something that's mostly sugar or carbohydrates to raise your blood sugar level quickly. Foods with a lot of fat, such as chocolate, don't work as well. Examples of foods that will raise your blood sugar level quickly include:
Five to six pieces of hard candy
Four ounces (118 milliliters) of fruit juice or regular — not diet — soda
One tablespoon (15 milliliters) of sugar, jelly or honey
Three glucose tablets (available without a prescription at most pharmacies)
If you experience symptoms of low blood sugar but can't check your blood sugar level right away, treat yourself as though you have hypoglycemia. In fact, you might want to carry at least one sugary item with you at all times. It's also a good idea to wear a bracelet that identifies you as someone who has diabetes.
Check your blood sugar level again 15 to 20 minutes later. If it's still too low, eat or drink something sugary. When you feel better, be sure to eat meals and snacks as usual.
Some people may still experience frequent and severe hypoglycemia despite medication adjustments .In these circumstances, your doctor may prescribe glucagon, a hormone that causes blood glucose to rise.
Glucagon is available by prescription only and comes in an emergency syringe kit. It contains one dose that has to be mixed before being injected. Store the glucagon at room temperature and be aware of the expiration date. Because vomiting can occur after an injection, you must be turned on your side to prevent choking if you're unconscious.
In 15 minutes you should be alert and able to swallow. You then need to eat. If you don't respond within 15 minutes, medical assistance should be called immediately.