Conditions & Treatments

Type 2 Diabetes

Type 2 diabetes is a metabolic disorder resulting from the body's inability to make enough, or to properly use, insulin.

Type 2 Diabetes

What is type 2 diabetes?

Type 2 diabetes is a metabolic disorder resulting from the body's inability to make enough insulin, or to properly use insulin. It used to be called non-insulin-dependent diabetes mellitus (NIDDM).

Without adequate production or utilization of insulin, the body cannot move blood sugar into the cells. Type 2 diabetes is a chronic disease that has no known cure. It is the most common type of diabetes.

What is prediabetes?

Type 2 diabetes is commonly preceded by prediabetes. In prediabetes, blood glucose levels are higher than normal but not high enough to be defined as diabetes. However, many people with prediabetes develop type 2 diabetes within 10 years, states the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Prediabetes also significantly increases the risk of heart disease and stroke. With modest weight loss and moderate physical activity, people with prediabetes can delay or prevent the progression to type 2 diabetes.

Prediabetes affects 79 million people age 20 or older in the U.S., according to the American Diabetes Association (ADA).

What causes type 2 diabetes?

The exact cause of type 2 diabetes is unknown. However, some genetic factors run in families and contribute to the risk of developing type 2 diabetes. Although a person can inherit a tendency to develop type 2 diabetes, it usually takes other factors, such as obesity or physical inactivity, to bring on the disease.

Prevention or delay of onset of type 2 diabetes

Type 2 diabetes may be prevented or delayed by following a program to eliminate or reduce risk factors, particularly losing weight and increasing exercise. Information gathered by the Diabetes Prevention Program, sponsored by the NIDDK and the ADA, continues to study this possibility.

What are the symptoms of type 2 diabetes?

The following are the most common symptoms of type 2 diabetes. However, each individual may experience symptoms differently. Symptoms may include:

  • Frequent bladder and skin infections that don't heal easily

  • High levels of sugar in the blood when tested

  • High levels of sugar in the urine when tested

  • Unusual thirst

  • Frequent urination

  • Weight loss despite an increase in appetite

  • Blurred vision

  • Nausea and vomiting

  • Extreme weakness and fatigue

  • Irritability and mood changes

  • Dry, itchy skin

  • Tingling or loss of feeling in the hands or feet

Some people who have type 2 diabetes exhibit no symptoms. Symptoms may be mild and almost unnoticeable, or easy to confuse with signs of aging. Half of all Americans who have diabetes do not know it.

The symptoms of type 2 diabetes may resemble other conditions or medical problems. Always consult your doctor for a diagnosis.

What are the risk factors for type 2 diabetes?

Risk factors for type 2 diabetes include the following:

  • 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. 

  • Pregnancy

  • History of gestational diabetes, or giving birth to a baby who weighed more than 9 pounds

  • A low blood level HDL (high-density lipoprotein--the "good cholesterol")

  • A high blood triglyceride level

What is the treatment for type 2 diabetes?

Specific treatment for type 2 diabetes will be determined by your doctor based on:

  • Your age, overall health, and medical history

  • Extent of the disease

  • Your tolerance for specific medications, procedures, or therapies

  • Expectations for the course of the disease

  • Your opinion or preference

The goal of treatment is to keep blood sugar levels as close to normal as possible.

Emphasis is on control of blood sugar (glucose) by monitoring the levels, regular physical activity, meal planning, and routine health care. Treatment of diabetes is an ongoing process of management and education that includes not only the person with diabetes, but also health care professionals and family members.

Often, type 2 diabetes can be controlled through losing weight, improved nutrition, and exercise alone. However, in some cases, these measures are not enough and either oral or injected medications and/or insulin must be used. Treatment often includes:

  • Proper diet

  • Weight control

  • An appropriate exercise program

  • Regular foot inspections

  • Oral medications, other medications, and/or insulin replacement therapy, as directed by your doctor. There are various types of medications that may be used to treat type 2 diabetes when lifestyle changes such as diet, exercise, and weight loss are not enough. Oral medications of several different types are available, with each type working in a different manner to lower blood sugar. One medication may be combined with another one to improve blood sugar control. When oral medications are no longer effective, insulin may be required.
    New medications for treating diabetes are in development.

  • Regular monitoring of the hemoglobin A1c levels. The hemoglobin A1c test (also called HbA1c test) shows the average amount of sugar in the blood over the last three months. The result will indicate if the blood sugar level is under control. The frequency of HbA1c testing will be determined by your doctor. It is recommended that testing occur at least twice a year if the blood sugar level is in the target range and stable, and more frequently if the blood sugar level is unstable.

Untreated or inappropriately-treated diabetes can cause problems with the kidneys, legs, feet, eyes, heart, nerves, and blood flow, which could lead to kidney failure, gangrene, amputation, blindness, or stroke. For these reasons, it is important to follow a strict treatment plan.

Advances in diabetes research have led to improved methods of managing diabetes and treating its complications. However, scientists continue to explore the causes of diabetes and ways to prevent and treat the disorder. Other methods of administering insulin through inhalers and pills are currently being studied. Scientists are investigating genetic factors involved in type 1 or type 2 diabetes, and some genetic markers for both types have been identified. Pancreas transplants are also being done in a research setting.  

Treatment Programs


Massachusetts General Hospital understands that a variety of factors influence patients' health care decisions. That's just one reason why we're dedicated to ensuring patients understand their diagnosis and treatment options. Because a single option might not serve all patients, we offer a wide range of coordinated treatments and related services across the hospital. Patients should consult with their primary care doctor or other qualified health care provider for medical advice and diagnosis information.

Select a treatment program for more information:



Digestive Healthcare Center

  • Weight Center
    The Massachusetts General Hospital Weight Center is a fully integrated center within the Digestive Healthcare Center that supports the spectrum of needs for people of all ages seeking help with obesity and weight loss.
Heart Center

  • Corrigan Women's Heart Health Program
    The Elizabeth Anne and Karen Barlow Corrigan Women's Heart Health Program at the Massachusetts General Hospital Corrigan Minehan Heart Center cares for women of all ages through prevention and early detection of heart disease.
  • Cardiovascular Disease Prevention Center
    The Cardiovascular Disease Prevention Center at the Massachusetts General Hospital Corrigan Minehan Heart Center takes a prevention-as-treatment approach to caring for the heart and overall cardiovascular system.
MassGeneral Hospital for Children

  • Pediatric Endocrine Program and Diabetes Center
    The Pediatric Endocrinology Program and Diabetes Center at MassGeneral Hospital for Children is an international referral center for the management of pediatric diabetes and endocrine disorders in children and adolescents.
  • Psychology Assessment Center
    The pediatric neuropsychology specialists at Massachusetts General Hospital’s Psychology Assessment Center provide neuropsychological assessments to aid in the diagnosis and treatment of neurological, medical, genetic and developmental disorders.
Diabetes Unit

  • Diabetes Eye Screening Programs
    Learn more about Diabetes Eye Screening Programs at Chelsea HealthCare Center Revere HealthCare Center.
  • Diabetes Self-Management Education and Support Program
    The Diabetes Self Management Education and Support (DSME/S) Program is an outpatient program designed for adults, children, and seniors with Type 1 or Type 2 Diabetes.
  • Diabetes Clinical Center
    The Mass General Diabetes Clinical Center is one of the oldest outpatient centers in the country dedicated to the comprehensive treatment of persons with diabetes, pre-diabetes, and associated disorders.
General and Gastrointestinal Surgery

  • Bariatric and Metabolic Surgery Program
    The Bariatric and Metabolic Surgery Program at Massachusetts General Hospital offers a full spectrum of safe and effective surgical procedures for obesity, weight disorders and metabolic disease.

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