Types of Diabetes

Under normal circumstances, the glucose (sugar) levels in your blood rise after you eat a meal or snack. In response, the body produces a hormone called insulin, which is necessary in order for the body to convert glucose in your bloodstream into usable energy. But if insulin isn’t available, or if the body isn’t using it correctly, your blood glucose will remain elevated, and that can be harmful to your body. The latter describes diabetes mellitus, a serious health condition that affects millions of people. There are actually three variations of this disease, but all characterized by abnormally high levels of glucose in the bloodstream.


Type 1 Diabetes


This form of diabetes is an autoimmune disorder, meaning your own immune system is damaging your body and causing the disease. In type 1 diabetes, the immune system attacks and destroys cells of the pancreas (called beta cells), which are the only cells in the body that manufacture insulin. Type 1 diabetes used to be called "insulin-dependent" because people with Type 1 diabetes must take insulin via pump or injection to survive. It is sometimes called "juvenile-onset" diabetes, because it usually makes its appearance during childhood or young adulthood. Between 5% and 10% of people with diabetes have type 1, which doesn't have a cure. Type 1 diabetics must work to manage the disease for the rest of their lives.

Who’s at risk?
No one knows exactly what causes type 1 diabetes. According to the Centers for Disease Control (CDC), the risk factors for developing type 1 diabetes include autoimmune, genetic, and environmental factors (such as viruses). While it’s most often diagnosed in children, type 1 diabetes can occur at any age and is most prevalent in Caucasians.

Can it be prevented?
Unfortunately, there is no way to prevent this form of diabetes.

What are the symptoms?
The destruction of the body’s beta cells can begin years before a person notices symptoms, which usually appear suddenly. These include: increased thirst and urination, persistent hunger, weight loss, blurred vision, and severe fatigue.

How is it treated?
Since they can’t make insulin on their own, people with type 1 diabetes must supply the body with insulin by using a pump or injections. Without a steady supply of insulin, type 1 diabetics can develop diabetic ketoacidosis, a life-threatening condition.


Type 2 Diabetes


In the early stages of type 2 diabetes, the pancreas is still manufacturing insulin, but for some reason the cells of the body are not using it properly—a condition known as insulin resistance. In response, the pancreas produces more and more insulin, wearing itself out and eventually losing its ability to produce insulin to keep blood glucose levels in the normal range. Similar to type 1 diabetes, high levels of blood glucose result, making it difficult for the body to use this glucose as fuel. Type 2 diabetes used to be called "non-insulin-dependent" or "adult-onset" or diabetes, but more and more cases are being diagnosed in children. Between 90% and 95% of diabetes cases are type 2. Like individuals with type 1, type 2 diabetics must also work to manage the disease for the rest of their lives.

Who’s at risk?
The risk factors for developing type 2 diabetes include advanced age, obesity (80% of people with type 2 diabetes are overweight), a family history of diabetes, a history of gestational diabetes (see below), physical inactivity, and race/ethnicity.  African Americans, Hispanic/Latino Americans, American Indians, Native Hawaiians and Pacific Islander Americans are at particularly high risk for type 2 diabetes.

Can it be prevented?
There are many ways to prevent this form of diabetes. Eating a healthy diet and getting sensible amounts of physical activity to achieve and maintain a healthy weight can help prevent or delay the development of type 2 diabetes.

What are the symptoms?
The symptoms of type 2 diabetes appear gradually, but some people who have type 2 diabetes won’t have any symptoms at all. Many symptoms are similar to those of type 1 diabetes, such as increased thirst, increased urination, weight loss, blurred vision and fatigue. Other signs include frequent infections and slow-healing wounds.

How is it treated?
People with type 2 diabetes can control their blood glucose levels by following a healthy diet and exercise program, losing excess weight and using medication prescribed by their doctors.


Gestational Diabetes


Some women develop this form of diabetes during the third trimester of pregnancy, in which the body still manufactures insulin, but pregnancy hormones prevent insulin from working properly. Treatment is necessary to prevent the abnormally high blood sugar levels from injuring the fetus.

Who’s at risk?
Gestational diabetes is more common among certain racial/ethnic groups (African Americans, Hispanic/Latino Americans, and American Indians). It also occurs more frequently among women who are over 25 years old, are obese, have a family history of diabetes, or have previously delivered a baby that weighed over 9 pounds. Although the gestational diabetes usually resolves itself after delivery, 5% to10% of women with gestational diabetes are diagnosed with type 2 diabetes after delivery, and 20% to 50% will develop type 2 diabetes within 10 years.

Can it be prevented?
The risk for developing gestational diabetes can be lowered by losing excess weight and staying physically active prior to conception, and then continuing to make healthy food choices and staying physically active during pregnancy. Women who have been diagnosed with gestational diabetes can lower their risk for developing type 2 diabetes by continuing these healthy habits after delivery, breastfeeding their children, and visiting their doctors regularly for checkups.

What are the symptoms?
Usually, gestational diabetes doesn’t have any symptoms. But when symptoms occur, they are very similar to those of both type 1 and type 2 diabetes: increased thirst and urination, persistent hunger, weight loss despite increases in appetite, blurred vision, and severe fatigue. Other signs include nausea, vomiting, and frequent infections to the bladder, vagina and/or skin.

How is it treated?
Since gestational diabetes can be problematic to your baby’s health and increase the risk of complications during delivery, treatment must begin right after diagnosis. This usually involves close monitoring and control of blood glucose levels by following a special eating plan (developed by your doctor and/or registered dietitian) and getting regular exercise. Some treatment plans may also include diabetes pills or insulin injections, if prescribed by your doctor.


If left unchecked, all forms of diabetes can cause serious health consequences. If you exhibit any of the symptoms of diabetes, or if you are at high-risk for developing it, talk to your doctor. It’s never too early to start a diabetes prevention program.
For more specific information or help, talk to your health care provider. The American Diabetes Association's National Call Center also offers live advice from 9 a.m. to 7 p.m. EST, Monday through Friday at 1-800-DIABETES or 1-800-342-2383.
This article has been reviewed and approved by Amy L. Poetker, MS, Registered Dietitian and Certified Diabetes Educator.