When you have diabetes, your body has difficulty regulating blood sugar. Having too much sugar in your blood can lead to health problems such as heart disease, kidney disease and eye problems. More than 9 percent of the U.S. population – more than 30 million people – have diabetes.
Types of diabetes
The two most common types of diabetes are type 1 and type 2. Type 1 diabetes occurs when the cells of the pancreas that produce insulin (islet cells) are destroyed. In type 2 diabetes the pancreas cannot make enough insulin and the cells of the body can’t use the insulin correctly. A third type, gestational diabetes, occurs only during pregnancy and women who develop this type of diabetes are at high risk for developing type 2 diabetes later in life.
Insulin is the hormone that controls the movement of glucose and other nutrients from the blood into cells. Insulin is produced by the pancreas. Glucose, also called blood sugar, constantly moves through the bloodstream in order to supply the body with the energy needed for muscle contractions and metabolism.
The job of insulin is to make sure glucose actually moves into the body's cells. Without insulin, glucose builds up in the bloodstream. Over time, elevated glucose levels can damage the linings of blood vessels, leading to damage to your eyes, kidneys and other sensitive tissues.
Other diabetes types and diabetes-related conditions include:
- Latent auto-immune diabetes of adulthood (LADA)
- Monogenic diabetes (mature onset diabetes of youth or MODY)
- Steroid-induced diabetes
- New onset diabetes after transplantation (NODAT)
- Hypoglycemia (low blood sugar)
- Diabetic ketoacidosis
- Diabetes foot and ankle problems
- Peripheral neuropathy (diabetic neuropathy)
- Obesity and diabetes
Symptoms of diabetes
Symptoms of very elevated blood glucose levels include:
- Increased thirst and urination
- Increased hunger
- Blurred vision
- Numbness or tingling in the feet or hands
- Sores that do not heal
- Unexplained weight loss
Symptoms of type 1 diabetes can start quickly, in a matter of weeks. Symptoms of type 2 diabetes often develop slowly and can be so mild that you might not notice them. Many people with type 2 diabetes have no symptoms. Some people do not find out they have the disease until they have diabetes-related health problems, such as blurred vision or heart trouble.
Causes of diabetes
Doctors and researchers are unsure what causes type 1 diabetes, but it is believed that genetic and environmental factors may be involved.
There appears to be a genetic factor to type 2 diabetes, the most common form of diabetes affecting more than 22 million Americans. Type 2 diabetes may be prevented or delayed if you eliminate or reduce risk factors, particularly by losing weight and increasing exercise.
Risk factors for type 2 diabetes include:
- Age – People age 45 or older are at higher risk for diabetes.
- Family history of diabetes
- Being overweight
- Not exercising regularly
- Race and ethnicity – Being a member of certain racial and ethnic groups increases the risk for type 2 diabetes. African-Americans, Hispanic Americans and American Indians are more prone to develop type 2 diabetes than white Americans.
- History of gestational diabetes or giving birth to a baby who weighed more than 9 pounds
- A low level of HDL (high-density lipoprotein – the "good cholesterol")
- A high triglyceride level