Everything You Need to Know About Type 2 Diabetes

Diabetes numbers are on the rise in the U.S. But smart prevention strategies can help keep the epidemic at bay.

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More than 30 million Americans have either type 1 or type 2 diabetes as of 2018, according to the Centers for Disease Control and Prevention (CDC). That’s about five times the number of people who had diabetes in 1980. Additionally, more than one in three Americans have prediabetes—higher-than-normal blood sugar—which puts them at increased risk for developing type 2 diabetes.

In March 2018, the CDC released a report breaking down those figures even further. An estimated 21 million American adults are thought to have type 2 diabetes—about 8.6 percent of the U.S. population over age 18. Approximately 1.3 million adults have type 1 diabetes, a comparatively small 0.55 percent of the adult population.

Diabetes is a serious condition that can potentially lead to heart trouble, kidney damage, blindness, loss of extremities or limbs and other disabling conditions. But with exercise, a healthy diet and the right medication, you can control your diabetes.

What's more, there's a growing consensus that weight loss could reverse type 2 diabetes for many—and it's increasingly backed by research. For example, one 2017 study published in The Lancet looked at about 300 people diagnosed with type 2 diabetes over the prior six years. Half were placed on a low-calorie liquid diet for up to five months, followed by therapy and a gradual reintroduction of foods. After a year, they had lost an average of 22 pounds—and a whopping 46 percent had gone into remission. Only 4 percent of the control group, who used their usual diabetes treatment regimens, had similar success with their diabetes.

Here’s what you need to know about diabetes, from diagnosis to treatment.

Medically reviewed in October 2018. Updated in October 2018.

Type 1 or type 2?

2 / 9 Type 1 or type 2?

Our bodies use glucose, a form of sugar, for energy. It’s absorbed into the bloodstream as the digestive system breaks down the food we eat. The pancreas makes a hormone called insulin, which carries your blood sugar to muscle, fat and liver cells. People develop diabetes when there’s not enough insulin to carry glucose from the blood to the cells, or when the cells become resistant to insulin.

In those with type 1 diabetes, the immune system destroys the insulin-producing cells in the pancreas, so those cells either don't produce enough insulin or they don't produce insulin at all. Type 2 diabetes occurs when the pancreas doesn’t make enough insulin, and most often develops during middle age.

Type 2 diabetes progression

3 / 9 Type 2 diabetes progression

The CDC estimates that 90 to 95 percent of people with diabetes have type 2 diabetes. Type 2 diabetes starts with insulin resistance, when your body can’t use insulin as efficiently as it once could to bring glucose into muscle, fat and liver cells. Glucose starts to build up in the bloodstream as the pancreas tries to keep up by making more insulin.

As long as the pancreas can meet the demand for more insulin, you’ll have normal blood sugar levels. If it can’t keep up, glucose builds in the bloodstream, a condition called hyperglycemia, which characterizes prediabetes. When prediabetes goes unchecked, it can eventually become type 2 diabetes.

Risk factors

4 / 9 Risk factors

Risk factors for type 2 diabetes include:

  • Being 45 years of age or older
  • Being of African American, Native American, Alaska Native, Asian American, Latino/Hispanic or Pacific Island descent
  • Being overweight, as indicated by a body mass index (BMI) of 25 or greater—unless you’re Asian American (23 or greater) or Pacific Islander (26 or greater)
  • A family history of diabetes
  • High blood pressure
  • Low level of HDL (“good”) cholesterol or high level of triglycerides
  • Low physical activity

5 / 9 Symptoms

Diabetes goes undiagnosed in nearly one-quarter of people who have it because symptoms can be mild and easy to miss. Common symptoms include:

  • frequent urination
  • abnormal hunger or thirst
  • extreme fatigue
  • slow-to-heal cuts and bruises
  • blurry vision
  • tingling, pain or numbness in the hands or feet
  • losing weight without trying to do so
Diagnosis and testing

6 / 9 Diagnosis and testing

Diabetes is diagnosed with a blood test. The most commonly used tests are the A1C test, the fasting blood sugar test, the glucose tolerance test and the random blood sugar test.

Once you’ve been diagnosed with diabetes, it’s important to monitor your blood sugar with a handheld meter. Typical targets are a pre-meal blood sugar level between 80 and 130 milligrams per deciliter (mg/dl) or post-meal blood sugar of less than 180 mg/dl.

The typical target for an A1C test is below 7 percent. You’ll likely receive the A1C test at least twice a year during doctor visits.


7 / 9 Complications

Heart disease is a common complication among people with diabetes. The CDC has estimated that 71 percent of adults with diabetes also have high blood pressure and 65 percent have high cholesterol. People with diabetes die from cardiovascular problems more often and they’re hospitalized for heart attack and stroke more often, as well, in part because high blood sugar levels damage blood vessels.

When small blood vessels are damaged, particularly in the eyes and kidneys, blindness and kidney failure may result. Nerve damage may also lead to loss of sensation and severe wounds in the feet. In extreme cases, amputation may be necessary.


8 / 9 Medication

Type 2 diabetes was thought to be irreversible, though recent studies have shown weight loss to be effective for some.

The condition can be managed with medication. Most type 2 diabetes treatment programs start with a drug called metformin, which improves the body’s ability to use insulin.

If blood sugar levels are still high after a few months, other treatments may be added to your care plan, such as insulin injections or drugs like sulfonylureas (which increase your body’s insulin production) or thiazolidinediones (which increase insulin sensitivity).

Prevention and management tips

9 / 9 Prevention and management tips

Keeping weight down is one of the most important things people can do for their diabetes. Exercise not only helps maintain a healthy weight, but it can help control your blood glucose, too. When you’re active, your cells can use insulin more effectively. Your muscles also pull glucose out of the blood to use for energy during physical activity. The CDC recommends getting at least 150 minutes of moderate-intensity exercise per week.

Eating a healthy diet high in fiber, tracking carbohydrates and consuming sugar and alcohol in moderation may also help control blood sugar levels.

more from this guide

Living Well With Type 2 Diabetes
5 Ways High Blood Sugar Damages the Body
Which Type of Exercise Is Best to Manage My Diabetes?
A Beginner's Guide to Exercising With Diabetes