Type 2 Diabetes
(Diabetes Mellitus Type 2; Insulin-Resistant Diabetes; Diabetes, Type 2)
by Debra Wood, RN
Diabetes is a condition that makes it difficult for the body to use or store glucose. Glucose is a type of sugar that cells use for energy. It comes from food, and is also created in the liver. Glucose travels through the body in the blood. A hormone called insulin helps to moves the glucose from the blood into cells. Insulin also helps to move glucose into the liver for storage if there is more in the blood than the body needs.
Diabetes can lead to a buildup of glucose in the blood. This form of diabetes is the most common type in adults. Medication, lifestyle changes, and monitoring can help control blood glucose levels.
Type 2 diabetes is often caused by a combination of factors. A main factor is that the body becomes resistant to insulin. This means there is insulin in the body, but the body cannot use it properly. Insulin resistance is often related to excess body fat. The body may also begin to make less insulin than is needed.
Type 2 diabetes is more common in people who are aged 45 years and older, but can develop in children. It is also common in younger people who are obese and belong to at-risk ethnic groups. Other factors that increase the chance of type 2 diabetes include:
Diabetes may be present for years before symptoms show.
Symptoms that may be caused by high blood sugar include:
Symptoms caused by chronic hyperglycemia may include
You will be asked about your symptoms, family, and medical history. A physical exam will be done.
Diabetes is based on the results of blood tests. American Diabetes Association (ADA) diagnoses diabetes if you have one of the following:
mg/dL = milligrams per deciliter of blood; mmol/L = millimole per liter of blood
You may also need blood tests to confirm diabetes is type 1 and not type 2. These may include:
Treatment aims to keep blood glucose as close to normal as possible. This can help to prevent or delay complications.
Diet, exercise, and weight loss are recommended for all patients. Most patients will also begin medication.
Food and drinks have a direct effect on blood glucose levels. Eating healthy meals can help control blood glucose. It will also help with your heart health and overall health. Some basic tips include:
In those who are overweight, weight loss will help the body use insulin better. Talk to the doctor about a healthy weight goal. A safe meal plan can be created.
To help with weight loss:
Physical activity can:
Aerobic exercise is any activity that increases heart rate. Resistance training helps build muscle strength. Both types of exercise help to improve long-term glucose control.
Aim for ≥ 150 minutes of physical activity each week. Talk to the doctor about an activity plan. Ask about any precautions that may be needed.
Non-insulin Glucose Lowering Medication
Medications other than insulin are typically used first to manage blood glucose levels.
Biguanides, usually metformin, are the first choice. They work by reducing the amount of glucose made by the body.
Insulin may be needed if:
Insulin is given through injections. There is one short-acting inhaled insulin which may be effective for select persons.
Blood Glucose Testing
Check the level of glucose in the blood with a blood glucose meter. Checking blood glucose levels during the day can help you stay on track. It will also help the doctor know if treatment is working. Keeping track of blood glucose levels is especially important for those taking insulin. Insulin can cause a very low level of blood glucose.
Regular testing may not be needed if diabetes is under control and insulin is not being taken. Talk with the doctor before stopping blood sugar monitoring.
An HbA1c test may also be done at the doctor's office. This is a measure of blood glucose control over a long period of time. Doctors advise that most people keep their HbA1c levels below 7%. Individual goals may be different. Keeping HbA1c in the goal range can help lower the chance of complications.
Depression can make good management more difficult. It also increases the risk of other complications. Feelings of sadness, hopelessness, and loss of interest in activities that last at least two weeks require a call to the doctor. Depression is treatable. Counseling can help better manage depression and diabetes.
Decreasing Risk of Complications
Over a long period of time, high blood glucose levels can damage vital organs. The risk of complications increases with poor blood glucose control. Common complications include:
Diabetes can also increase the risk of heart disease.
Reaching your blood glucose and HbA1c levels is the first step to lowering the risk of these complications. Other steps that can help include:
To help reduce your chance of type 2 diabetes:
American Diabetes Association
National Diabetes Information Clearinghouse
Canadian Diabetes Association
Public Health Agency of Canada
American Association of Clinical Endocrinologists, American College of Endocrinology. Comprehensive Type 2 Diabetes Management Algorithm 2017. Endocr Pract. 2017 Feb;23(2):207-238.
American Diabetes Association Classification and Diagnosis of Diabetes of Diabetes Mellitus. Diabetes Care. 2015 Jan;38 Suppl:S8-S16.
Symptoms & Causes of Diabetes. National Institute of Diabetes and Digestive and Kidney Diseases website. Available at: https://www.niddk.nih.gov/health-information/diabetes/overview/symptoms-causes. Updated November 2016. Accessed August 25, 2017.
Diabetes. Centers for Disease Control and Prevention website. Available at:
...(Click grey area to select URL)
Updated July 25, 2016. Accessed August 25, 2017.
Diabetes mellitus type 2 in adults. EBSCO DynaMed Plus website. Available at: http://www.dynamed... . Updated August 25, 2017. Accessed August 25, 2017.
Diabetes mellitus type 2 in children and adolescents. EBSCO DynaMed Plus website. Available at: http://www.dynamed... . Updated July 18, 2017. Accessed August 25, 2017.
Dietary considerations for patients with type 2 diabetes. EBSCO DynaMed Plus website. Available at: http://www.dynamed... . Updated February 7, 2017. Accessed August 25, 2017.
Traina AN, Kane MP. Primer on pramlintide, an amylin analog. Diabetes Educ. 2011;37(3):426-431.
Type 2. American Diabetes Association website. Available at:
...(Click grey area to select URL)
Accessed September 19, 2017.
9/16/2014 DynaMed Plus Systematic Literature Surveillance http://www.dynamed... : Zhou D, Yu H, He F, et al. Nut consumption in relation to cardiovascular disease risk and type 2 diabetes: a systematic review and meta-analysis of prospective studies. Am J Clin Nutr. 2014;100(1):270-277.
12/14/2016 DynaMed Plus Systematic Literature Surveillance http://www.dynamed... : Shen HN, Yang CC, Chang YH, Lu CL, Li CY. Risk of diabetes mellitus after first-attack acute pancreatitis: a national population-based study. Am J Gastroenterol. 2015;110(12):1698-1706.
10/1/2018 DynaMed Plus Systematic Literature Surveillance http://www.dynamed... : Mantovani A, Byrne CD, Bonora E, Targher G. Nonalcoholic fatty liver disease and risk of incident type 2 diabetes: a meta-analysis. Diabetes Care. 2018;41(2):372-382.
Last reviewed September 2018 by EBSCO Medical Review Board Michael Woods, MD, FAAP
Last Updated: 10/1/2018
EBSCO Information Services is fully accredited by URAC. URAC is an independent, nonprofit health care accrediting organization dedicated to promoting health care quality through accreditation, certification and commendation.
This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.
To send comments or feedback to our Editorial Team regarding the content please email us at email@example.com. Our Health Library Support team will respond to your email request within 2 business days.