What is diabetes mellitus?
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:
- The pancreas (an organ behind your stomach) produces little insulin or no insulin at all. Insulin is a naturally occurring hormone, produced by the beta cells of the pancreas, which helps the body use sugar for energy.
- The pancreas makes insulin, but the insulin made does not work as it should. This condition is called insulin resistance.
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 cannot 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 cannot 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).
What are the types of diabetes?
There are two main types of diabetes: type 1 and type 2:
- Type 1 diabetes occurs because the insulin-producing cells of the pancreas (beta cells) are damaged. In type 1 diabetes, the pancreas makes little or no insulin, so sugar cannot get into the body's cells for use as energy. People with type 1 diabetes must use insulin injections to control their blood glucose. Type 1 is the most common form of diabetes in people who are under age 30, but it can occur at any age. Ten percent of people with diabetes are diagnosed with type 1.
- In type 2 diabetes (adult onset diabetes), the pancreas makes insulin, but it either doesn't produce enough, or the insulin does not work properly. Nine out of 10 people with diabetes have type 2. This type occurs most often in people who are over 40 years old but can occur even in childhood if there are risk factors present. Type 2 diabetes may sometimes be controlled with a combination of diet, weight management and exercise. However, treatment also may include oral glucose-lowering medications (taken by mouth) or insulin injections (shots).
Other types of diabetes might result from pregnancy (gestational diabetes), surgery, use of certain medicines, various illnesses and other specific causes.
What is gestational diabetes?
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:
- Are over 35 years old
- Are overweight
- Have a family history of diabetes
- Have a history of polycystic ovarian syndrome
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.
What causes diabetes?
The causes of diabetes are not known. The following risk factors may increase your chance of getting diabetes:
- Family history of diabetes
- African-American, Hispanic, Native American, or Asian-American race, Pacific Islander or ethnic background
- Being overweight
- Physical stress (such as surgery or illness)
- Use of certain medications, including steroids
- Injury to the pancreas (such as infection, tumor, surgery or accident)
- Autoimmune disease
- High blood pressure
- Abnormal blood cholesterol or triglyceride levels
- Age (risk increases with age)
- History of gestational diabetes
It is important to note that sugar itself does not cause diabetes. Eating a lot of sugar can lead to tooth decay, but it does not cause diabetes.
What are the symptoms of diabetes?
The symptoms of diabetes include:
- Increased thirst
- Increased hunger (especially after eating)
- Dry mouth
- Frequent urination
- Unexplained weight loss (even though you are eating and feel hungry)
- Weak, tired feeling
- Blurred vision
- Numbness or tingling in the hands or feet
- Slow-healing sores or cuts
- Dry and itchy skin
- Frequent yeast infections or urinary tract infections
What are the symptoms of low blood sugar?
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:
- Feeling weak
- Feeling dizzy
- Feeling hungry
- Trembling and feeling shaky
- Pounding heart
- Pale skin
- Feeling frightened or anxious
Late symptoms of low blood sugar include:
- Feeling confused
- Feeling cranky
- Poor coordination
- Bad dreams or nightmares
- Being unable keep your mind on one subject
- Numbness in your mouth and tongue
- Passing out