What Is Type 2 Diabetes? Symptoms, Causes, Diagnosis, Treatment, and Prevention
Type 2 diabetes, a form of diabetes mellitus, is likely one of the better-known chronic diseases in the world — and it makes sense that this would be the case. Data suggests in the United States alone, 37.3 million people, or 11.3 percent of the U.S. population, have diabetes, and the majority of these people have type 2.
Whether you've been diagnosed with type 2 diabetes or have a family history of the disease, this condition and the risk for health complications that may come with it can be scary. And with the required diet and lifestyle changes, there's no question that this diagnosis can be a challenging one to reckon with.
But living with type 2 diabetes doesn’t have to be devastating. In fact, when you're educated about the disease — such as understanding how insulin resistance develops and how to mitigate it, knowing how to spot the signs of diabetes, and learning what to eat — you can tap into the resources you need to lead a happy, healthy life.
Furthermore, there’s increasing evidence that one tactic — bariatric surgery — could reverse type 2 diabetes entirely.
In this article, delve into this information and so much more. Sit back, read on, and get ready to take charge of type 2 diabetes.
Common Questions & Answers
These days, there's a lot of talk about reversing diabetes. But the truth is experts haven't found a cure for the disease yet. The good news is you may be able to put type 2 diabetes in remission by following a healthy, low-carb diet; exercising; and possibly taking medication.
Signs and Symptoms of Type 2 Diabetes
- Frequent urination and extreme thirst
- Sudden or unexpected weight loss
- Increased hunger
- Blurry vision
- Dark, velvety patches of skin (called acanthosis nigricans)
- Fatigue
- Wounds that won’t heal
If you have one or more risk factors for type 2 diabetes and notice any of these signs, it’s a good idea to call your doctor, as you may have type 2 diabetes.
What Are the Early Symptoms of Type 2 Diabetes?
Causes and Risk Factors of Type 2 Diabetes
Insulin Resistance
Prediabetes
Type 2 Diabetes Risk Factors
As mentioned, type 2 diabetes is a multifactorial disease. That means you can’t just stop eating sugar or start exercising to avoid developing this health condition.
Here are some of the factors that may affect your risk of type 2 diabetes.
Is Type 2 Diabetes Genetic?
Independent of diet and lifestyle factors, your genetics can affect your risk of type 2 diabetes, too.
How Is Type 2 Diabetes Diagnosed?
Glycated hemoglobin (A1C) test A1C is a two- to three-month measurement of your average blood sugar levels. While an A1C of 5.7 or below is normal, anything between 5.7 and 6.4 percent signals prediabetes and a reading of 6.5 percent or higher on two different tests suggests you have diabetes.
A1C and fasting glucose are common tests used to diagnose diabetes, but if you’re pregnant or have a hemoglobin variant, your doctor may use another method, such as:
- Oral glucose tolerance test
- Random blood sugar test
Prognosis of Type 2 Diabetes
Don’t lose hope, though. You don’t have to be a statistic. Receiving a prompt diagnosis can help you get your health on track and reduce your risk of complications.
Indeed, if you take care to manage your blood sugar by following a healthy diet, exercising regularly, taking your prescribed medication, and losing weight, you may find your quality of life to be better with diabetes than it was before your diagnosis.
7 Tips for Aging Well With Type 2 Diabetes
Duration of Type 2 Diabetes
Although changes to your diet and lifestyle, and oral and injectable medication (such as insulin) can help manage type 2 diabetes, the disease's underlying predisposition for insulin resistance cannot be cured.
Hyperglycemia and Hypoglycemia
If you have type 2 diabetes, you’re at risk of high blood sugar and low blood sugar. Preventing these episodes requires knowing the signs, causes, and treatment options to get your blood sugar back in a healthy range.
Hyperglycemia (High Blood Sugar)
High blood sugar doesn't always produce symptoms, so it's important to check your blood sugar regularly, as indicated by your doctor.
- Frequent urination
- Extreme thirst
- Feeling tired and weak
- Blurry vision
- Feeling hungry, even after eating
If you've been diagnosed with type 2 diabetes, you can work with your doctor to devise a treatment plan to keep it as close to a healthy range as possible.
Even after you start treatment, you may still develop hyperglycemia at times.
- Missing prescribed medicines or taking medication at the wrong times or in the wrong amounts
- Eating large portions, especially of foods with more carbs than intended or expected
- Not getting enough sleep
- Experiencing emotional stress
- Doing intense exercise
- Having an illness or infection
Hypoglycemia (Low Blood Sugar)
Although low blood sugar is more common in people with type 1 diabetes, people with type 2 diabetes can also develop this condition, especially if they are using insulin.
- Your body's supply of glucose is used up too quickly.
- Glucose is released into your bloodstream too slowly.
- There's too much insulin in your bloodstream.
- Sudden, intense hunger
- Dizziness or light-headedness
- Excessive sweating (often sudden and without regard to temperature)
- Shaking or tremors
- Sudden feelings of anxiety
- Irritability, mood swings, and sudden emotional outbursts that aren't part of your normal behavior
- Confusion or inability to concentrate
- Weakness or drowsiness
- Blurry vision
- Slurred speech
- Sleep disturbances, including night sweats, nightmares, waking suddenly and crying out, or feelings of confusion upon waking
- If hypoglycemia isn't treated right away, low blood sugar may result in life-threatening complications, such as seizure or coma, or even death.
People with diabetes may become hypoglycemic when they:
- Take their insulin or oral diabetes medication but then skip a meal, delay eating, or eat very little
- Develop it as a side effect of other diabetes medication
- Exercise strenuously without adequate food intake
- Drink too much alcohol
If you have type 2 diabetes, you've probably had a conversation with your doctor about how to treat yourself for low blood sugar.
- Glucose tablets
- Glucose gel
- Juice or regular soda (not diet)
- Sugar, honey, or corn syrup
- Raisins
- Hard candies, jelly beans, or gumdrops
Treatment and Medication Options for Type 2 Diabetes
If you’ve been diagnosed with type 2 diabetes, you have various treatment options at your disposal.
Medication Options
For example, you may be prescribed the oral medication metformin (Glucophage), which can help lower your blood sugar levels.
While metformin is the first-line medication for individuals with type 2 diabetes, it’s not the only diabetes medication at your disposal.
Others include:
GLP-1 Receptor and GIP Agonists Tirzepatide (Mounjaro) is the first drug in this class to be commercially available. It activates the GLP-1 and GIP receptors, leading to improved blood sugar control and weight loss, according to the U.S. Food and Drug Administration (FDA).
Complementary and Integrative Health Approaches
Apart from these conventional medication treatment options, effective diabetes management means taking a well-rounded approach: You’ll need to eat well, exercise, manage stress, and sleep enough, because all these factors can affect your blood sugar levels.
Certain complementary approaches may help support your conventional diabetes care, including certain botanical therapies, supplements, traditional Chinese medicine, mind-body therapies, and special diets like keto, research shows.
Self-Care
How Much Do You Know About Type 2 Diabetes?
Insulin Options for Type 2 Diabetes
If you’re unable to control your blood sugar with oral or noninsulin injectable medication, diet, and lifestyle, you may need to add basal or bolus insulin to your treatment regimen.
Here's how they differ.
Bariatric Surgery and Type 2 Diabetes
Type 2 Diabetes Diet: What Can You Eat?
Learn More About What to Eat and Avoid if You Have Type 2 Diabetes
Keto Diet for Type 2 Diabetes: Does It Work?
Learn More About Diabetic Ketoacidosis
Learn More About the Ketogenic Diet for Type 2 Diabetes
Prevention of Type 2 Diabetes
Complications of Type 2 Diabetes
If you have been diagnosed with type 2 diabetes, you may have anxiety or concerns about the prospect of future health complications, such as amputations, heart disease, and vision loss. But living with this disease doesn’t destine you for these unpleasant outcomes.
Preventing Type 2 Diabetes Complications
- Blood sugar control
- Blood pressure control
- Blood cholesterol control
You should discuss your level of control (and how to maintain or improve it) with your doctor at every doctor’s appointment.
Health Problems Linked to Type 2 Diabetes
If your blood sugar is frequently imbalanced, you may be at a greater risk for the following type 2 diabetes complications.
Diabetic retinopathy In diabetic retinopathy, high blood sugar weakens the capillaries (the tiny blood vessels) that supply the retina, the light-sensitive layer of tissue at the back of the inner eye.
The capillaries then swell, become blocked, or leak blood into the center of the eye, blurring vision. In advanced stages, abnormal new blood vessels grow.
Diabetic neuropathy Neuropathy, or nerve damage, can affect any nerve in your body. Most commonly, it affects the nerves in the feet, legs, hands, and arms; this condition is called peripheral neuropathy.
Peripheral neuropathy can cause tingling, burning, pain, or numbness in the affected areas.
The pain of peripheral neuropathy is difficult to control, though some find topical products that contain capsaicin to be helpful.
Diabetic nephropathy (kidney disease) In diabetic nephropathy, the nephrons (or filtering units) in the kidneys become damaged from chronic high blood sugar.
High blood pressure compounds the problem, and high cholesterol appears to contribute to it as well.
In the early stages of diabetic nephropathy, you may not notice any symptoms, but standard blood and urine tests can detect early signs of dysfunction, and early treatment can stop or slow its progression.
Diabetic ulcer People with diabetes have an increased risk of developing foot ulcers (open sores).
A diabetic ulcer is often painless, and people may not even know they have them at first.
These foot ulcers can take several weeks to heal, and are a primary reason for hospital stays among people with diabetes.
If you have diabetes, you may also deal with sexual issues, gum disease, sleep apnea, and red or brown lesions (diabetic dermopathy).
Learn More About the Most Common Diabetes Complications and How to Prevent Them
Research and Statistics: Who Has Type 2 Diabetes?
BIPOC and Type 2 Diabetes
Diabetes Prevalence
Complications of Diabetes
Death Rates
Possible Driving Factors Behind Health Disparities
Related Conditions and Causes of Type 2 Diabetes
While the cause of type 2 diabetes is multifactorial, meaning there’s no single cause, certain conditions exist in conjunction with this condition.
- Obesity
- Heart disease
- Peripheral vascular disease
- Stroke
- Neuropathy
- Nephropathy
- Retinopathy
- Glaucoma
- Cataracts
Tips for Aging Well With Type 2 Diabetes
- Lean on your medical team, which may consist of an endocrinologist, a podiatrist, an RDN and a CDCES, and other specialty health professionals such as a therapist for mental healthcare. In many cases, your primary care physician will be your main healthcare provider for diabetes care.
- Stick to your medication regimen, and be open to potential medication adjustments.
- Take insulin if your doctor says you need it.
- Don’t smoke, or quit the habit.
- Eat diabetes-friendly foods and practice portion control.
- Exercise regularly.
- Regularly check your blood sugar.
Type 2 Diabetes and COVID-19
The CDC points out that having type 2 diabetes can make it more likely that you will experience complications from COVID-19, the disease caused by the novel coronavirus. Nonetheless, proper blood sugar management can help lessen this risk.
Resources We Love
Favorite Orgs for Essential Diabetes Info
American Diabetes Care and Education Specialists (ADCES) Meeting
Everyday Health editors attend the ADCES annual meeting to connect with certified diabetes care and education specialists, registered dietitian nutritionists, and people like you, who are looking for ways to better manage blood sugar, diet, medication, and more. Check out information on the next meeting here.
American Diabetes Association (ADA)
The ADA is considered the leading nonprofit for type 1 and type 2 diabetes education. The ADA's free yearlong program Living With Diabetes offers top-of-the-line resources for anyone new to living with diabetes. You’ll get access to their newsletter, expert Q&A session, and online support system, among other perks.
American Heart Association (AHA)
One of our favorite features from the AHA is a go-to resource for preventing heart disease: Know Diabetes by Heart. The ADA-supported initiative lays out a step-by-step guide for keeping your heart healthy while living with diabetes.
Favorite Alternative Medicine Resource
Cleveland Clinic Functional Ketogenics Program
Want to give the ketogenic (“keto”) diet a whirl to better manage diabetes? This pioneering program from the Cleveland Clinic offers a way to do just that, with trained counselors who can help you adjust your diet and medication along the way.
Favorite Online Support Networks
Enter this website, and you’ll immediately feel less alone in your diabetes journey. They’ve got loads of inspiring patient stories in addition to their forum, which helps you connect with others managing diabetes.
These sisters truly have your back when it comes to using insulin at the dinner table, making your emotional health a priority, and all the other stuff you don’t know how to bring up with your diabetes care team. They rotate bloggers on a three- to six-month basis to share their diabetes journeys in their own words. And don’t let the site name fool you: “Diabetes Misters” are welcome too.
For more of our favorite diabetes blogs, check out our list.
Favorite Site for Diabetes Products
Diabetes Forecast Consumer Guide
The FOMO on diabetes products ends now. This feature by the magazine and website Diabetes Forecast rounds up the best of the best in CGMs (continuous glucose monitors), glucagon kits, insulin pens, and more.
Favorite Resource for Diet Advice
Giving up some of the foods you once loved is arguably the biggest bummer about receiving a diabetes diagnosis. But with this Harvard-affiliated organization’s expert diet guidance, you don’t have to.
For more on "bad" foods you can eat in a diabetes diet, check out our article "5 'Bad' Diabetes Foods You Can Enjoy in Moderation."
Favorite Resource for Becoming an Advocate
International Diabetes Federation (IDF)
Want to get involved? The IDF, which reaches 168 countries, makes it easy with their advocacy network page. You’ll find different organizations that you can work with to help propel diabetes research, legislation, and awareness.
Favorite App
mySugr
If you’re looking to home in on your A1C goal, this app’s for you. It lets you analyze dips and rises in your blood sugar, offers education about blood sugar management, allows you to work with a CDE virtually, and even links data from certain diabetes devices.
For more of our favorite diabetes apps, check out our list.
Editorial Sources and Fact-Checking
- National Diabetes Statistics Report. Centers for Disease Control and Prevention. January 18, 2022.
- Huo L, Magliano DJ, Rancière F, et al. Impact of Age at Diagnosis and Duration of Type 2 Diabetes on Mortality in Australia 1997–2011. Diabetologia. May 2018.
- Kmietowicz Z. GP Based Weight Loss Programme Can Reverse Type 2 Diabetes. BMJ. December 5, 2017.
- Westman EC, Tondt J, Maguire E, et al. Implementing a Low-Carbohydrate, Ketogenic Diet to Manage Type 2 Diabetes Mellitus. Expert Review of Endocrinology & Metabolism. September 2018.
- Screening for Type 2 Diabetes. Diabetes Care. January 2004.
- Type 2 Diabetes: Symptoms and Causes. Mayo Clinic. January 9, 2019.
- Risk Factors for Type 2 Diabetes. National Institute of Diabetes and Digestive and Kidney Diseases. November 2016.
- Prediabetes and Insulin Resistance. National Institute of Diabetes and Digestive and Kidney Diseases. May 2018.
- Brown AE, Walker M. Genetics of Insulin Resistance and the Metabolic Syndrome. Current Cardiology Reports. June 2016.
- Losing Weight, Body Mass Index. National Heart, Lung, and Blood Institute.
- Nutrition Overview. American Diabetes Association.
- Television Watching and “Sit Time.” Harvard T.H. Chan School of Public Health Obesity Prevention Source.
- Preventing Diabetes. John Muir Health.
- Sleep Longer to Lower Blood Glucose Levels. National Sleep Foundation.
- Rubin KH, Glintborg D, Nybo M, et al. Development and Risk Factors of Type 2 Diabetes in a Nationwide Population of Women With Polycystic Ovary Syndrome. Journal of Clinical Endocrinology & Metabolism. August 29, 2017.
- Loved Ones. American Diabetes Association.
- McCarthy M, Menzel S. The Genetics of Type 2 Diabetes. British Journal of Clinical Pharmacology. March 2001.
- Spanakis EK, Golden SH. Race/Ethnic Difference in Diabetes and Diabetic Complications. Current Diabetes Reports. December 2013.
- Classification and Diagnosis of Diabetes. Diabetes Care. January 2019.
- Type 2 Diabetes: Diagnosis and Treatment. Mayo Clinic. January 9, 2019.
- Blood Sugar Test. MedlinePlus.
- Deshpande AD, Harris-Hayes M, Schootman M. Epidemiology of Diabetes and Diabetes-Related Complications. Physical Therapy. November 2008.
- Jansson SPO, Andersson DKG, Svärdsudd K. Mortality Trends in Subjects With and Without Diabetes During 33 Years of Follow-Up. Diabetes Care. March 2010.
- People at Risk for Type 2 Diabetes. Centers for Disease Control and Prevention.
- Type 2 Diabetes Mellitus. Harvard Health Publishing. December 2018.
- Campbell A. What Is a Normal Blood Sugar Level? Diabetes Self-Management. July 15, 2019.
- Diabetes Diet: Create Your Healthy-Eating Plan. Mayo Clinic.
- Hyperglycemia (High Blood Glucose). American Diabetes Association.
- Low Blood Sugar — Self Care. MedlinePlus. May 17, 2018.
- Hypoglycemia: Symptoms and Causes. Mayo Clinic. March 13, 2020.
- Hypoglycemia (Low Blood Glucose). American Diabetes Association.
- Drugs@FDA. U.S. Food and Drug Administration.
- FDA Approves First Treatment for Severe Hypoglycemia That Can Be Administered Without an Injection. U.S. Food and Drug Administration. July 24, 2019.
- Sulfonylureas and Meglitinides. John Hopkins Patient Guide to Diabetes.
- Marino M. Alpha-Glucosidase Inhibitors. Diabetes Self-Management. November 20, 2014.
- Thiazolidinediones (Glitazones) — Suitability, Benefits, and Side Effects. Diabetes.co.uk. January 15, 2019.
- Incretin Mimetics (GLP-1 Agonists). Diabetes.co.uk. January 15, 2019.
- DPP-4 Inhibitors (Gliptins) — Drugs, Suitability, Benefits & Side Effects. Diabetes.co.uk. January 15, 2019.
- Kalra S. Sodium Glucose Co-Transporter-2 (SGLT2) Inhibitors: A Review of Their Basic and Clinical Pharmacology. Diabetes Therapy. December 2014.
- Holt RIG, de Groot M, Golden SH. Diabetes and Depression. Current Diabetes Reports. April 18, 2014.
- Yin J, Wong R, Shimen A, et al. Effects of Providing Peer Support on Diabetes Management in People With Type 2 Diabetes. Annals of Family Medicine. August 2015.
- Basal Insulins (Intermediate and Long-Acting). John Hopkins Patient Guide to Diabetes.
- Basal Bolus — Basal Bolus Injection Regimen. Diabetes.co.uk.
- Buchwald H, Buchwald JN. Metabolic (Bariatric and Nonbariatric) Surgery for Type 2 Diabetes: A Personal Perspective Review. Diabetes Care. February 2019.
- Sjöström L. Review of the Key Results From the Swedish Obese Subjects (SOS) Trial — A Prospective Controlled Intervention Study of Bariatric Surgery. Journal of Internal Medicine. March 2013.
- Post RE, Mainous AG 3rd, King DE, et al. Dietary Fiber for the Treatment of Type 2 Diabetes Mellitus: A Meta-Analysis. Journal of the American Board of Family Medicine. January–February 2012.
- Benson G, Pereira RF, Boucher JL. Rationale for the Use of a Mediterranean Diet in Diabetes Management. Diabetes Spectrum. February 2011.
- Get Smart on Carb Counting. American Diabetes Association.
- Diabetic Ketoacidosis. Mayo Clinic. June 12, 2018.
- Paoli A, Rubini A, Volek SJ, et al. Beyond Weight Loss: A Review of the Therapeutic Uses of Very-Low-Carbohydrate (Ketogenic) Diets. European Journal of Clinical Nutrition. August 2013.
- Hallberg SJ, McKenzie AL, Williams PT, et al. Effectiveness and Safety of a Novel Care Model for the Management of Type 2 Diabetes at 1 Year: An Open-Label, Nonrandomized, Controlled Study. Diabetes Therapy. April 2018.
- Paoli A. Ketogenic Diet for Obesity: Friend or Foe? International Journal of Environmental Research and Public Health. February 2014.
- Morrison F, Shubina M, Turchin A. Encounter Frequency and Blood Glucose, Blood Pressure and Cholesterol Control in Patients with Diabetes. Archives of Internal Medicine. September 26, 2011.
- Litwak L, Goh S-Y, Hussein Z, et al. Prevalence of Diabetes Complications in People With Type 2 Diabetes Mellitus and Its Association With Baseline Characteristics in the Multinational A1chieve Study. Diabetology & Metabolic Syndrome. October 24, 2013.
- Ischemic Heart Disease. National Heart, Lung, and Blood Institute.
- Diabetes, Heart Disease, and You. Centers for Disease Control and Prevention. November 23, 2016.
- Preventing Heart Disease: What You Can Do. Centers for Disease Control and Prevention. August 10, 2015.
- Diabetic Retinopathy. American Optometric Association.
- Diabetic Neuropathy: Symptoms and Causes. Mayo Clinic. September 7, 2018.
- Diabetic Nephropathy: Symptoms and Causes. Mayo Clinic. September 19, 2019.
- Amputation and Diabetes: How to Protect Your Feet. Mayo Clinic. August 8, 2017.
- Diabetes. World Health Organization. October 30, 2018.
- Diabetes: Preventing Complications. Cleveland Clinic. March 29, 2017.
- Cherrington AL, Kodneva Y, Richman JS, et al. Impact of Peer Support on Acute Care Visits and Hospitalizations for Individuals With Diabetes and Depressive Symptoms: A Cluster Randomized Controlled Trial. Diabetes Care. October 2018.
- Kirkman MS, Briscoe VJ, Clark N, et al. Diabetes in Older Adults. Journal of the American Geriatrics Society. December 2012.
- People With Certain Medical Conditions. Centers for Disease Control and Prevention. November 2, 2020.
- National Diabetes Statistics Report 2020. Centers for Disease Control and Prevention.
- Diabetes Risk Factors. Centers for Disease Control and Prevention. March 24, 2020.
- Mayer-Davis EJ, Lawrence JM, Dabelea D, et al. Incidence Trends of Type 1 and Type 2 Diabetes among Youths, 2002–2012. New England Journal of Medicine. April 13, 2017.
- Fighting Diabetes' Deadly Impact on Minorities. U.S. Food and Drug Administration. April 10, 2020.
- Diabetes and African Americans. U.S. Department of Health and Human Services: Office of Minority Health. December 19, 2019.
- Wang Y, Katzmarzyk PT, Horswell R, et al. Racial Disparities in Diabetic Complications in an Underinsured Population. Journal of Clinical Endocrinology and Metabolism. December 1, 2012.
- McBean AM, Shuling L, Gilbertson DT, et al. Differences in Diabetes Prevalence, Incidence, and Mortality Among the Elderly of Four Racial/Ethnic Groups: Whites, Blacks, Hispanics, and Asians. Diabetes Care. October 2004.
- Rosenstock S, Whitman S, West JF, et al. Racial Disparities in Diabetes Mortality in the 50 Most Populous US Cities. Journal of Urban Health. October 2014.
- Bell CN, Thorpe RJ, Bowie JV, et al. Race Disparities in Cardiovascular Disease Risk Factors Within Socioeconomic Status Strata. Annals of Epidemiology. March 2018.
- Sohn H. Racial and Ethnic Disparities in Health Insurance Coverage: Dynamics of Gaining and Losing Coverage Over the Life-Course. Population Research and Policy Review. January 4, 2018.
- Understanding Racial and Ethnic Differences in Health in Late Life: A Research Agenda. National Research Council (US) Panel on Race, Ethnicity, and Health in Later Life. 2004.
- Whyte MB, Hinton W, McGovern A, et al. Disparities in Glycaemic Control, Monitoring, and Treatment of Type 2 Diabetes in England: A Retrospective Cohort Analysis. PLoS Medicine. October 7, 2019.
- Canedo JR, Miller ST, Schlundt D, et al. Racial/Ethnic Disparities in Diabetes Quality of Care: The Role of Healthcare Access and Socioeconomic Status. Journal of Racial and Ethnic Health Disparities. February 2018.
- Tung EL, Baig AA, Huang ES, et al. Racial and Ethnic Disparities in Diabetes Screening Between Asian Americans and Other Adults: BRFSS 2012–2014. Journal of General Internal Medicine. November 15, 2016.
- Medagama AB, Bandara R. The Use of Complementary and Alternative Medicine (CAMs) in the Treatment of Diabetes Mellitus: Is Continued Use Safe and Effective? Nutrition Journal. 2014.