Patient education: Low blood sugar in people with diabetes (The Basics)

What is low blood sugar? — Low blood sugar is a condition that can cause symptoms ranging from sweating and feeling hungry to passing out. Low blood sugar, which is also called "hypoglycemia," happens when the level of sugar in a person's blood gets too low.

Low blood sugar can happen in people with diabetes (sometimes called "diabetes mellitus") who take certain diabetes medicines, including insulin and some types of pills.

When can people with diabetes get low blood sugar? — People with diabetes can get low blood sugar when they:

●Take too much medicine, including insulin or certain diabetes pills

●Do not eat enough food

●Exercise too much without eating a snack or reducing their insulin dose

●Wait too long between meals

●Drink too much alcohol

What are the symptoms of low blood sugar? — The symptoms of low blood sugar can be different from person to person, and can change over time. During the early stages of low blood sugar, a person can:

●Sweat or tremble

●Feel hungry

●Feel worried

People who have early symptoms should check their blood sugar level to see if it is low and needs to be treated. If low blood sugar levels are not treated, severe symptoms can occur. These can include:

●Trouble walking or feeling weak

●Trouble seeing clearly

●Being confused or acting in a strange way

●Passing out or having a seizure

Some people do not get symptoms during the early stages of low blood sugar. Doctors call this "hypoglycemia unawareness." People with hypoglycemia unawareness are more likely to have severe symptoms, because they might not know that they have low blood sugar until they have severe symptoms. Hypoglycemia unawareness often occurs in people who:

●Have had type 1 diabetes for more than 5 to 10 years

●Use insulin to keep their blood sugar level under tight control

●Are tired

●Drink a lot of alcohol

●Take certain medicines for high blood pressure or diabetes

How is low blood sugar treated? — Low blood sugar can be treated with:

●Quick sources of sugar – People can treat low blood sugar by eating or drinking quick sources of sugar (table 1). Foods that have fat, such as chocolate or cheese, do not treat low blood sugar as quickly. You and a family member should carry a quick source of sugar at all times.

●A dose of glucagon – Glucagon is a hormone that can quickly raise blood sugar levels and stop severe symptoms. It comes as a shot (figure 1) or a nose spray. If your doctor recommends that you carry glucagon with you, they will tell you when and how to use it. If possible, it's also a good idea to have a family member, friend, or roommate learn how to give you glucagon. That way they can give it to you if you can't do it yourself.

What should I do after treatment? — After treatment for low blood sugar, most people can get back to their usual routine. But your doctor or nurse might recommend that you check your blood sugar level more often during the next 2 to 3 days.

If your low blood sugar was treated with glucagon, call your doctor or nurse. They might change the dose of your diabetes medicine.

How can I prevent low blood sugar? — The best way to prevent low blood sugar is to:

●Check your blood sugar levels often – Your doctor or nurse will tell you how and when to check your blood sugar levels at home. They will also tell you what your blood sugar levels should be, and when to treat low blood sugar.

●Learn the symptoms of low blood sugar and be ready to treat it in the early stages. Treating low blood sugar early can prevent severe symptoms.

When should I go to a hospital or call for an ambulance? — A family member or friend should take you to a hospital or call for an ambulance (in the US and Canada, call 9-1-1) if you:

●Are still confused 15 minutes after being treated with a dose of glucagon

●Have passed out and there is no glucagon nearby

●Still have low blood sugar after treatment

If you have low blood sugar, do not try to drive yourself to the hospital. Driving with low blood sugar can be dangerous.

More on this topic

Patient education: Type 1 diabetes (The Basics)
Patient education: Type 2 diabetes (The Basics)
Patient education: Using insulin (The Basics)
Patient education: Treatment for type 2 diabetes (The Basics)
Patient education: Seizures (The Basics)

Patient education: Hypoglycemia (low blood glucose) in people with diabetes (Beyond the Basics)
Patient education: Blood glucose monitoring in diabetes (Beyond the Basics)
Patient education: Type 1 diabetes: Insulin treatment (Beyond the Basics)
Patient education: Type 2 diabetes: Insulin treatment (Beyond the Basics)
Patient education: Type 2 diabetes: Treatment (Beyond the Basics)