Skip to content
My WebMD Sign In, Sign Up

Diabetes Health Center

Font Size
A
A
A

The NIDDK on Hypoglycemia

Glucose, a form of sugar, is the body's main fuel. Hypoglycemia, or low blood sugar, occurs when blood levels of glucose drop too low to fuel the body's activity.

Carbohydrates (sugars and starches) are the body's main dietary sources of glucose. During digestion, the glucose is absorbed into the blood stream (hence the term "blood sugar"), which carries it to every cell in the body. Unused glucose is stored in the liver as glycogen.

Recommended Related to Diabetes

Is Stevia a Good Substitute for Sugar?

In every issue of WebMD the Magazine, we ask our experts to answer readers' questions about a wide range of topics. In our January-February 2011 issue, we asked WebMD's Diabetes Expert, Michael Dansinger, MD, whether stevia, a new natural sweetener, is a good sugar substitute for people with diabetes.   

Read the Is Stevia a Good Substitute for Sugar? article > >

Hypoglycemia can occur as a complication of diabetes, as a condition in itself, or in association with other disorders.

Blood Sugar Range

The normal range for blood sugar is about 60 mg/dL (milligrams of glucose per deciliter of blood) to 120 mg/dL, depending on when a person last ate. In the fasting state, blood sugar can occasionally fall below 60 mg/dL and even to below 50 mg/dL and not indicate a serious abnormality or disease. This can be seen in healthy women, particularly after prolonged fasting. Blood sugar levels below 45 mg/dL are almost always associated with a serious abnormality.

How Does the Body Control Glucose?

The amount of glucose in the blood is controlled mainly by the hormones insulin and glucagon. Too much or too little of these hormones can cause blood sugar levels to fall too low (hypoglycemia) or rise too high (hyperglycemia). Other hormones that influence blood sugar levels are cortisol, growth hormone, and catecholamines (epinephrine and norepinephrine).

The pancreas, a gland in the upper abdomen, produces insulin and glucagon. The pancreas is dotted with hormone-producing tissue called the islets of Langerhans, which contain alpha and beta cells. When blood sugar rises after a meal, the beta cells release insulin. The insulin helps glucose enter body cells, lowering blood levels of glucose to the normal range. When blood sugar drops too low, the alpha cells secrete glucagon. This signals the liver to release stored glycogen and change it back to glucose, raising blood sugar levels to the normal range. Muscles also store glycogen that can be converted to glucose.

What Are the Symptoms of Hypoglycemia?

A person with hypoglycemia may feel weak, drowsy, confused, hungry, and dizzy. Paleness, headache, irritability, trembling, sweating, rapid heart beat, and a cold, clammy feeling are also signs of low blood sugar. In severe cases, a person can lose consciousness and even lapse into a coma.

The symptoms associated with hypoglycemia are sometimes mistaken for symptoms caused by conditions not related to blood sugar. For example, unusual stress and anxiety can cause excess production of catecholamines, resulting in symptoms similar to those caused by hypoglycemia but having no relation to blood sugar levels.

Hypoglycemia in Diabetes

The most common cause of hypoglycemia is as a complication of diabetes. Diabetes occurs when the body cannot use glucose for fuel because either the pancreas is not able to make enough insulin or the insulin that is available is not effective. As a result, glucose builds up in the blood instead of getting into body cells.

1 | 2 | 3 | 4 | 5

WebMD Public Information from the U.S. National Institutes of Health

Is This Normal? Get the Facts Fast!

Check Your Blood Sugar Level Now
What type of diabetes do you have?
Your gender:

Get the latest Diabetes newsletter delivered to your inbox!


or
Answer:
Low
0-69
Normal
70-130
High
131+

Your level is currently

If the level is below 70 and you are experiencing symptoms such as shaking, sweating or difficulty thinking, you will need to raise the number immediately. A quick solution is to eat a few pieces of hard candy or 1 tablespoon of sugar or honey. Recheck your numbers again in 15 minutes to see if the number has gone up. If not, repeat the steps above or call your doctor.

People who experience hypoglycemia several times in a week should call their health care provider. It's important to monitor your levels each day so you can make sure your numbers are within the range. If you are pregnant always consult with your health care provider.

Congratulations on taking steps to manage your health.

However, it's important to continue to track your numbers so that you can make lifestyle changes if needed. If you are pregnant always consult with your physician.

Your level is high if this reading was taken before eating. Aim for 70-130 before meals and less than 180 two hours after meals.

Even if your number is high, it's not too late for you to take control of your health and lower your blood sugar.

One of the first steps is to monitor your levels each day. If you are pregnant always consult with your physician.

Did You Know Your Lifestyle Choices
Affect Your Blood Sugar?

Use the Blood Glucose Tracker to monitor
how well you manage your blood sugar over time.

Get Started

This tool is not intended for women who are pregnant.

Start Over

Step:  of 

Today on WebMD

Woman holding cake
Slideshow
feet
Slideshow
 
man organizing pills
Slideshow
Close up of eye
Slideshow
 

Woman serving fast food from window
Video
Can Vinegar Treat Diabetes
Video
 
Middle aged person
Tool
are battery operated toothbrushes really better
Video
 

Prediabetes How to Prevent Type 2 Diabetes
Article
type 2 diabetes
Slideshow
 
food fitness planner
Tool
Are You at Risk for Dupuytrens Contracture
Article
 

WebMD Special Sections