Since the two types of diabetes — type 1 and type 2 — are similar in some ways and different in others, it’s important to understand the characteristics they share as well as how each type is unique.
Diabetes: Type 1 vs. Type 2
One key distinction between type 1 and type 2 diabetes involves insulin — the hormone your body needs to convert the sugar and starches from the food you eat into blood sugar, or energy for your cells. In type 1 diabetes, the body doesn’t produce insulin. In type 2 diabetes, the body doesn’t respond properly to the insulin it produces.
“With type 1 diabetes, the lack of insulin is absolute, and with type 2 diabetes, it’s a relative decrease,” explains Andrew J. Drexler, MD, professor of medicine at the David Geffen School of Medicine at UCLA and medical director of the UCLA Gonda Diabetes Center in Los Angeles.
Fewer than 10 percent of people with diabetes in the United States have type 1 diabetes. Type 1 diabetes used to be called “juvenile diabetes” because it was typically diagnosed in children and young adults, Dr. Drexler says, and most often around age 4 or at the onset of puberty. “However, we’re finding that some people develop type 1 diabetes later in life,” he says.
Type 2 diabetes is the more common form of diabetes, affecting at least 90 percent of people who have the condition. Type 2 diabetes used to be called “adult-onset diabetes” because it commonly affected people in their forties. “Now we’re seeing type 2 diabetes in a growing number of adolescents,” Drexler says, “probably because more kids and teens are overweight, have unhealthy diets, and don’t exercise.”
Type 2 diabetes is no longer referred to as “insulin-resistant” either, Drexler notes, because some people with type 2 need to use insulin, though most often that happens a long time after the onset of their diabetes.
Diabetes Causes and Risk Factors
Researchers know how type 1 diabetes occurs. “The body mistakes its insulin-producing cells as foreign invaders, and the immune system tries to destroy them as it does any foreign tissue,” Drexler says. However, no one knows why this or any other autoimmune disease occurs in some people and not others, he adds.
There are few known risk factors for type 1 diabetes. Some possible risk factors include family history, genetics, and exposure to certain viruses such as Epstein-Barr virus, a human herpes virus.
Research shows that people who are overweight and inactive are at greater risk for developing type 2 diabetes. But like with type 1, researchers don’t know why some people develop type 2 diabetes and others don’t. One possibility is that excess fat makes it harder for your cells to respond to insulin. Other risk factors for type 2 diabetes include family history and race, with African-Americans, Hispanics, American Indians, and Asian Americans at greater risk than whites.
The symptoms of type 1 and type 2 diabetes are similar and include increased thirst, more frequent urination, constant hunger, weight loss, blurred vision, and extreme fatigue. However, the symptoms of type 2 diabetes develop more slowly than the symptoms of type 1 diabetes, and some people with type 2 diabetes have no symptoms at all.
Type 1 diabetes is treated with insulin that must be injected into the fat under your skin so that it gets into your bloodstream. “The only medication for type 1 diabetes is insulin,” Drexler says. Most people choose injections, but some use insulin pumps that continuously deliver insulin through a catheter placed under the skin.
In many cases, type 2 diabetes can be prevented or controlled with diet and exercise. Studies show that people who lose even a small amount of weight may be able to control their blood sugar levels and not need medication. If you can’t control your type 2 diabetes with diet and exercise, your doctor may give you medication to lower your blood sugar levels.
Over the last few decades, great strides have been made in diabetes treatment for both type 1 and type 2 diabetes. “Type 1 diabetes is still more difficult to control,” Drexler says, “although now we’re able to control it well enough that most people don’t develop its serious complications.” These include blindness, kidney failure, peripheral nerve damage, heart disease, and heart attacks.
“We can’t cure type 1 diabetes, but we can prevent it from having the impact it did on people’s lives in the past,” he says. “That’s true for type 2 diabetes as well. For example, the incidence of heart attacks in people with diabetes, which used to be the major killer, is finally going down.”
Drexler credits this heart-health improvement to people with diabetes becoming more aware of how to better manage their disease, and to advances in the diabetes treatments available.
If you think you have symptoms of diabetes, talk with your doctor and get tested. Whether you have type 1 or type 2 diabetes, if you work closely with your healthcare team you can keep your condition under control to avoid complications and live healthier.