Diabetes mellitus is a disease that prevents your body from properly using the energy from the food you eat. Diabetes occurs in one of the following situations:
To better understand diabetes, it helps to know more about how the body uses food for energy (a process called metabolism).
Your body is made up of millions of cells. To make energy, the cells need food in a very simple form. When you eat or drink, much of your food is broken down into a simple sugar called glucose. Glucose provides the energy your body needs for daily activities.
The blood vessels and blood are the highways that transport sugar from where it is either taken in (the stomach) or manufactured (in the liver) to the cells where it is used (muscles) or where it is stored (fat). Sugar isn't able to go into the cells by itself. The pancreas releases insulin into the blood, which serves as the helper, or the "key," that lets sugar into the cells for use as energy.
When sugar leaves the bloodstream and enters the cells, the blood sugar level is lowered. Without insulin, or the "key," sugar can't get into the body's cells for use as energy. This causes sugar to rise. Too much sugar in the blood is called "hyperglycemia" (high blood sugar).
There are two main types of diabetes: Type 1 and Type 2:
Other types of diabetes might result from pregnancy (gestational diabetes), surgery, use of certain medicines, various illnesses and other specific causes.
Gestational diabetes occurs when there is a high blood glucose level during pregnancy. As pregnancy progresses, the developing baby has a greater need for glucose. Hormone changes during pregnancy also affect the action of insulin, which brings about high blood glucose levels.
Pregnant women who have a greater risk of developing gestational diabetes include those who:
Blood glucose levels usually return to normal after childbirth. However, women who have had gestational diabetes have an increased risk of developing Type 2 diabetes later in life.
The causes of diabetes are not known. The following risk factors may increase your chance of getting diabetes:
There are risk factors that you might have more control over, including:
It is important to note that sugar itself doesn't cause diabetes. Eating a lot of sugar can lead to tooth decay, but it doesn't cause diabetes.
The symptoms of diabetes include:
Other symptoms include:
Most people have symptoms of low blood sugar (hypoglycemia) when their blood sugar is less than 70 mg/dl. (Your healthcare provider will tell you how to test your blood sugar level.)
When your blood sugar is low, your body gives out signs that you need food. Different people have different symptoms. You will learn to know your symptoms.
Common early symptoms of low blood sugar include the following:
Late symptoms of low blood sugar include:
Diabetes is diagnosed with fasting sugar blood tests or with A1c blood tests, also known as glycated hemoglobin tests. A fasting blood sugar test is performed after you have had nothing to eat or drink for at least eight hours. Normal fasting blood sugar is less than 100 mg/dl (5.6 mmol/l). You do not have to be fasting for an A1c blood test. Diabetes is diagnosed by one of the following (see chart):
An A1c test should be performed in a laboratory using a method that is certified by the National Glycohemoglobin Standardization Program (NGSP) and standardized to the Diabetes Control and Complications Trial (DCCT) assay.
|Type of test||Normal||Pre-diabetes||Diabetes|
Less than 100
|100-125||126 or higher|
Less than 140
|140-199||200 or higher|
Less than 5.7%
|5.7 - 6.4%||6.5% or higher|
There is no cure for diabetes, but it can be treated and controlled. The goals of managing diabetes are to:
You hold the keys to managing your diabetes by:
What you do at home every day affects your blood glucose more than what your doctor can do every few months during your check-up.
Insulin pumps are small, computerized devices, about the size of a small cell phone that you wear on your belt, in your pocket, or under your clothes. They deliver rapid-acting insulin 24 hours a day through a small flexible tube called a cannula. The cannula is inserted under the skin using a needle. The needle is then removed leaving only the flexible tube under the skin. The pump user replaces the cannula every two to three days.
An insulin pump can deliver insulin 24 hours a day.
It is important for pump users to frequently monitor their glucose levels either with a continuous glucose monitor or a fingerstick monitor. The pump delivers a continuous flow of insulin that can be adjusted if needed for things like exercise and stress. A pump user regularly enters information about their food intake and blood sugar levels into the pump so it can help them calculate insulin doses for food intake and high blood sugar levels.
Benefits of an insulin pump include fewer insulin injections, a more flexible lifestyle, and a more consistent and adjustable delivery of insulin.
Yes. The combination of insulin and an oral medication, when taken as directed by your healthcare provider, is very safe and effective in controlling blood sugar. A typical combination therapy consists of taking an oral medication during the day and insulin at night.
Once you begin taking insulin, you will need to monitor your blood sugar more often to reduce the risk of low blood sugar reactions. Combination therapies are often helpful for people who have Type 2 diabetes. If you have been taking an oral medication, your doctor may change your treatment plan to include insulin injections. This change is often made to help people with Type 2 diabetes gain better control of their blood sugar.
Although diabetes risk factors like family history cannot be changed, there are other risk factors that you do have some control over. Implementing some of the healthy lifestyle habits below can improve these modifiable risk factors and help to decrease your chances of getting Type 2 diabetes:
Other long-term complications may include:
Last reviewed by a Cleveland Clinic medical professional on 10/02/2018.