Very high or very low blood sugar can become life-threatening fast. Call 911 or go to the nearest emergency room if you or someone with diabetes has: nausea and vomiting, fruity-smelling breath, rapid or deep breathing, abdominal pain, and confusion (possible diabetic ketoacidosis, or DKA—which can occur in type 2 diabetes, especially in people taking an SGLT2 inhibitor, sometimes even when blood sugar is not extremely high); very high blood sugar with severe dehydration, extreme thirst, and confusion (possible hyperosmolar hyperglycemic state, or HHS); or confusion, seizure, or loss of consciousness from low blood sugar (severe hypoglycemia). Do not try to drive yourself. Never stop insulin or diabetes medicine on your own—that can trigger a crisis.
More than 38 million Americans are living with diabetes, and roughly 90% to 95% of them have type 2 diabetes, according to the Centers for Disease Control and Prevention. The CDC’s National Diabetes Statistics Report puts the total at about 38.4 million people, and what makes the condition especially concerning is how many go undetected: an estimated 8.7 million adults have diabetes and do not yet know it, while roughly 97.6 million adults have prediabetes. Understanding this condition—how it develops, what it looks like, and what you can do about it—is one of the most important steps you can take for your long-term health. For a broader look at how common chronic conditions affect millions of Americans, see our medical conditions guide. This article is general education, not medical advice.
What Is Type 2 Diabetes?
Type 2 diabetes is a chronic metabolic disorder characterized by insulin resistance and, eventually, impaired insulin production. Your body still produces insulin—the hormone that allows glucose to enter your cells for energy—but your cells don’t respond to it effectively. Over time, your pancreas can’t keep up with the increased demand, and blood sugar levels rise into harmful ranges.
This differs from type 1 diabetes, which is an autoimmune condition where the body attacks its insulin-producing cells entirely. Type 2 diabetes develops gradually, often over years, and is closely linked to lifestyle factors, genetics, and metabolic health. The condition was once called “adult-onset diabetes,” but that term has been largely abandoned because increasing numbers of children and adolescents are now being diagnosed.
According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), type 2 diabetes is the most common form of diabetes worldwide and a leading contributor to heart disease, kidney failure, vision loss, and lower-limb amputation. The encouraging counterpoint is that it is also one of the most modifiable chronic diseases: the same day-to-day choices that drive it are the ones that can slow, control, and sometimes reverse it.
Causes and Risk Factors
Type 2 diabetes doesn’t have a single cause. It results from a combination of genetic predisposition and environmental triggers. If you have a parent or sibling with type 2 diabetes, your risk is significantly higher—research has identified hundreds of genetic variants associated with the condition, though genes set the stage rather than seal the outcome.
Excess body weight—particularly visceral fat stored around the abdomen—is the strongest modifiable risk factor. Fat tissue, especially in the belly area, promotes inflammation and releases signaling molecules that make cells more resistant to insulin. Physical inactivity compounds this problem. When muscles aren’t used regularly, they become less efficient at absorbing glucose from the bloodstream.
Other well-established risk factors include age (risk rises after 45, though it is increasingly seen younger), a history of gestational diabetes, polycystic ovary syndrome (PCOS), high blood pressure, abnormal cholesterol, and belonging to certain racial or ethnic groups. African American, Hispanic/Latino, American Indian, Alaska Native, and some Asian American populations face disproportionately higher rates. Prediabetes—where blood sugar is elevated but not yet at diabetic levels—affects tens of millions of American adults and is the single most important precursor to intervene on.
The Role of Insulin Resistance
Insulin resistance is the hallmark mechanism. When cells in your muscles, liver, and fat tissue stop responding normally to insulin, your pancreas compensates by producing more. This works for a while, but eventually the beta cells in your pancreas become overworked and can’t maintain the elevated output. Blood sugar begins to climb, first into prediabetic ranges and then into full diabetes.
Chronic low-grade inflammation, excess free fatty acids in the blood, and disruptions in gut microbiome composition have all been implicated in the progression from insulin resistance to type 2 diabetes. Research from the National Institutes of Health suggests that inflammation-driven pathways may offer future targets for prevention, though for now the proven levers remain weight, activity, diet, and, when needed, medication.
Recognizing the Symptoms
One of the most dangerous aspects of type 2 diabetes is how quietly it develops. Many people have elevated blood sugar for years before symptoms become noticeable. When they do appear, the classic signs include increased thirst (polydipsia), frequent urination (polyuria), unexplained weight loss, and persistent fatigue.
You may also notice blurred vision, slow-healing cuts or sores, numbness or tingling in your hands or feet, and frequent infections—particularly yeast infections or urinary tract infections. Darkened patches of skin, known as acanthosis nigricans, often appear on the neck, armpits, or groin and can be an early visible marker of insulin resistance.
Because symptoms develop so gradually, the CDC recommends that all adults aged 35 and older be screened for type 2 diabetes, with earlier and more frequent screening for those who carry risk factors such as excess weight, a family history, prior gestational diabetes, or prediabetes. Don’t wait for symptoms to prompt a visit—by the time you feel something is off, the disease may have been quietly doing damage for years.
Diagnosis and Testing
Several blood tests can diagnose type 2 diabetes. The most commonly used is the A1C test (also called hemoglobin A1C or HbA1c), which measures your average blood sugar over the past two to three months. An A1C of 6.5% or higher on two separate tests indicates diabetes. Results between 5.7% and 6.4% indicate prediabetes.
The fasting plasma glucose (FPG) test measures blood sugar after an overnight fast; a result of 126 mg/dL or higher suggests diabetes. The oral glucose tolerance test (OGTT) involves drinking a sugary solution and checking blood sugar two hours later—a reading of 200 mg/dL or above is diagnostic. A random blood sugar of 200 mg/dL or higher, combined with symptoms, can also confirm the diagnosis. These specific thresholds are set by clinical guidelines and are periodically reviewed, so your clinician interprets your numbers in the context of your overall health.
Your doctor may order additional tests to distinguish type 2 from type 1 diabetes, including C-peptide levels (which reflect how much insulin your body is producing) and autoantibody tests. Accurate classification matters because the treatment approaches differ significantly, and a subset of adults have slower-onset autoimmune diabetes that can be mistaken for type 2.
Complications: What Uncontrolled Diabetes Does to Your Body
Chronically elevated blood sugar damages blood vessels and nerves throughout the body, so the complications of type 2 diabetes are wide-ranging and can be severe. Cardiovascular disease is the leading cause of death among people with type 2 diabetes—they are substantially more likely to have a heart attack or stroke than someone without diabetes, which is why blood pressure and cholesterol control are treated as core parts of diabetes care.
Diabetic kidney disease (nephropathy) affects roughly one in three adults with diabetes and is a leading cause of kidney failure requiring dialysis. Diabetic retinopathy damages blood vessels in the retina and is a common cause of new vision loss in working-age adults. Peripheral neuropathy—nerve damage in the extremities—causes pain, numbness, and increases the risk of foot ulcers and amputation, which is why annual foot and eye exams are standard.
Other complications include increased susceptibility to infections, gastroparesis (delayed stomach emptying), sexual dysfunction, hearing impairment, gum disease, and an elevated risk of cognitive decline. The Mayo Clinic notes that nearly every organ system can be affected by poorly managed diabetes over time. The good news is that tight, sustained blood sugar, blood pressure, and cholesterol control meaningfully reduces the risk of every one of these outcomes.
Diabetic Emergencies to Take Seriously
Beyond the slow-burning complications above, type 2 diabetes can produce acute emergencies. These are uncommon with good day-to-day control, but everyone with diabetes and their loved ones should recognize them.
Diabetic ketoacidosis (DKA): Once considered mainly a type 1 problem, DKA can occur in type 2 diabetes too—particularly in people taking an SGLT2 inhibitor, where it can develop even when blood sugar is only mildly elevated (“euglycemic DKA”). Warning signs include nausea and vomiting, abdominal pain, deep or rapid breathing, fruity-smelling breath, excessive thirst, and confusion. Hyperosmolar hyperglycemic state (HHS): very high blood sugar (often above 600 mg/dL) with severe dehydration, weakness, and confusion, most common in older adults. Severe hypoglycemia: blood sugar below 70 mg/dL that progresses to confusion, seizures, or loss of consciousness. Any of these needs emergency care—call 911. If someone is conscious and able to swallow, treat low blood sugar with fast-acting carbohydrate first; if they cannot, do not force food and call 911.
Treatment Options
Treatment for type 2 diabetes typically follows a stepped, individualized approach, starting with lifestyle changes and adding medications as needed. The overarching goal is to reach an A1C target your doctor sets for you (often below 7%, but higher or lower depending on age, other conditions, and hypoglycemia risk) while protecting your heart, kidneys, and quality of life. Every element below should be directed by a clinician—this guide intentionally gives no doses.
Lifestyle Modifications
Diet and exercise are the foundation of type 2 diabetes management. The NIDDK recommends focusing on portion control, choosing minimally processed carbohydrates over refined ones, increasing fiber, and limiting added sugars and saturated fats. There is no single “diabetes diet”—what matters is finding a sustainable eating pattern that helps control blood sugar and that you can actually keep up.
Physical activity improves insulin sensitivity directly. Guidelines generally recommend about 150 minutes per week of moderate-intensity activity—brisk walking, cycling, swimming—plus muscle-strengthening on two or more days. Even short walks after meals can meaningfully blunt blood sugar spikes. Losing 5% to 7% of body weight has been shown to significantly improve blood sugar control, and larger, sustained weight loss earlier in the disease is associated in some people with remission.
Medications
Metformin remains the first-line medication for most people with type 2 diabetes. It works primarily by reducing glucose production in the liver and improving insulin sensitivity. It has been used for decades, has a well-understood safety profile, and is inexpensive. Side effects are mostly gastrointestinal and often improve with the extended-release formulation or by taking it with food.
When lifestyle and metformin aren’t enough—or when someone has heart or kidney disease—clinicians increasingly choose the next medication for its added protective benefits, not just its glucose-lowering. Two classes stand out:
- GLP-1 and dual GIP/GLP-1 receptor drugs. GLP-1 receptor agonists (such as semaglutide and liraglutide) and the dual GIP/GLP-1 receptor agonist tirzepatide lower blood sugar, promote substantial weight loss, and—for several agents in the class—have shown cardiovascular and, in some cases, kidney benefit in large trials. They have become central to modern type 2 diabetes care, especially for people who also have obesity or heart disease.
- SGLT2 inhibitors. Drugs such as empagliflozin and dapagliflozin lower blood sugar by prompting the kidneys to excrete excess glucose, and they have demonstrated meaningful benefits for heart failure and chronic kidney disease independent of blood sugar. Because they carry a small risk of DKA (including euglycemic DKA) and genital infections, they require the awareness described in the emergency box above.
Other medication classes include sulfonylureas, DPP-4 inhibitors, thiazolidinediones, and insulin—which many people with type 2 diabetes eventually need as pancreatic function declines over the years. Insulin is not a failure or a last resort; it is simply a tool, and for some people the safest one. Your treatment plan should be tailored to your A1C, other health conditions, kidney function, medication costs, and preferences. Because several of these medicines are expensive, understanding healthcare costs and coverage can help you and your clinician choose a regimen you can sustain. Whatever your regimen, do not start, stop, switch, or skip doses of any diabetes medicine or insulin on your own—stopping abruptly can cause blood sugar to surge and, in some cases, precipitate an emergency.
Blood Sugar Monitoring
Regular blood sugar monitoring helps you understand how food, activity, stress, illness, and medications affect your glucose. Traditional monitoring involves pricking your finger and using a glucose meter at specific times—usually before meals and at bedtime, if your plan calls for it.
Continuous glucose monitors (CGMs) have transformed diabetes management for many people. These small skin-worn devices measure glucose in interstitial fluid every few minutes and send readings to a smartphone or receiver, complete with trend arrows showing whether glucose is rising, falling, or stable. CGM use in type 2 diabetes has been associated with improved A1C and less time spent in high ranges, and several CGMs are now available over the counter, though whether one is right for you—and whether it is covered—depends on your treatment and insurer.
Your doctor will also check your A1C every three to six months. That single number gives a picture of overall control and is the primary metric used to guide treatment decisions, alongside your day-to-day readings and time-in-range data if you use a CGM.
The Role of Diet in Managing Type 2 Diabetes
What you eat has a direct, measurable impact on your blood sugar. Carbohydrates raise blood sugar the most, which is why carb awareness is central to diabetes nutrition. This doesn’t mean eliminating carbs—it means choosing the right types and amounts.
Whole grains, legumes, vegetables, and whole fruits (in sensible portions) provide carbohydrates along with fiber, which slows glucose absorption. Refined carbs—white bread, sugary cereals, pastries—cause rapid spikes. Protein and healthy fats have minimal direct impact on blood sugar and can help you feel full longer.
The Mediterranean diet, the DASH diet, and plant-forward eating patterns have all shown benefits for people with type 2 diabetes in clinical studies. The Mayo Clinic emphasizes that consistency matters—eating roughly similar amounts of carbohydrate at similar times makes blood sugar more predictable and easier to manage. A registered dietitian or certified diabetes care and education specialist can help you translate these principles into a plan that fits your culture, budget, and routine.
Alcohol deserves special mention. It can cause both high and low blood sugar depending on how much you drink and whether you eat alongside it. If you drink, do so in moderation and always with food, and be aware that alcohol can mask the early warning signs of hypoglycemia.
Prevention: Can Type 2 Diabetes Be Avoided?
For many people, the answer is yes—or at least significantly delayed. The landmark Diabetes Prevention Program (DPP) demonstrated that structured lifestyle intervention reduced the risk of developing type 2 diabetes by 58% in people with prediabetes, and by 71% among participants aged 60 and older. These results were more effective than metformin, which reduced risk by about 31%.
The key interventions were straightforward: lose 5% to 7% of body weight (roughly 10 to 14 pounds for someone weighing 200 pounds) and get at least 150 minutes of moderate physical activity per week. Participants didn’t need extreme diets or punishing exercise—consistent, moderate changes produced dramatic results, and the benefit persisted for years in long-term follow-up.
If you’ve been told you have prediabetes, this is the critical window. The CDC’s National Diabetes Prevention Program offers recognized lifestyle-change programs across the country, many covered by insurance. Getting screened, knowing your numbers, and acting on prediabetes may be one of the most cost-effective health decisions you ever make.
Understanding Remission
“Remission”—not “cure”—is the term experts now use when blood sugar returns to non-diabetic levels without ongoing glucose-lowering medication, usually after meaningful weight loss achieved through intensive lifestyle change or metabolic (bariatric) surgery. Remission is most achievable earlier in the disease and with larger, sustained weight loss. It is a genuine and worthwhile goal, but the underlying predisposition remains: blood sugar can drift back into the diabetic range if weight is regained or the disease progresses, so continued monitoring is important even in remission. Whether remission is realistic for you is a conversation to have with your clinician rather than a promise to chase through unproven supplements.
Frequently Asked Questions
Can type 2 diabetes be reversed?
Type 2 diabetes can go into remission, particularly with significant weight loss early in the disease. Clinical trials have shown that a meaningful share of people who lose a large amount of weight—often around 15 kg or more—can achieve remission, and metabolic surgery produces remission in many patients. “Remission” is the preferred term over “reversal” because the underlying tendency remains and blood sugar can return to diabetic levels if weight is regained. Any plan to reduce or stop medication as part of remission should be supervised by your clinician.
What is the difference between type 1 and type 2 diabetes?
Type 1 diabetes is an autoimmune disease in which the immune system destroys insulin-producing beta cells, requiring lifelong insulin from diagnosis. Type 2 diabetes involves insulin resistance and progressive loss of beta-cell function, and can often be managed initially with lifestyle changes and non-insulin medications. Type 2 accounts for the large majority of all diabetes cases.
How often should I check my blood sugar if I have type 2 diabetes?
It depends on your treatment plan. If you take insulin, your doctor may recommend checking several times daily. If you manage with non-insulin medications and lifestyle changes, you may check less often—or rely on periodic A1C testing and a CGM. Your healthcare provider will set a monitoring schedule based on your situation and how well-controlled your blood sugar is.
Does eating sugar cause type 2 diabetes?
Eating sugar alone doesn’t directly cause type 2 diabetes. However, a diet high in added sugars and refined carbohydrates contributes to weight gain, which is the strongest modifiable risk factor. Sugary beverages in particular have been linked to increased risk in multiple large studies. The relationship is indirect but real.
What blood sugar level is considered dangerous?
Blood sugar below 70 mg/dL is hypoglycemia and needs prompt treatment with fast-acting carbohydrate; if it drops low enough to cause confusion or loss of consciousness, that is an emergency. On the high end, very elevated readings (for example, persistently above 250 mg/dL, and especially above 600 mg/dL) can signal DKA or HHS and require urgent medical attention. Call 911 for confusion, extreme thirst with very high readings, difficulty breathing, fruity-smelling breath, vomiting that prevents you from keeping fluids down, or loss of consciousness.
Do I have to take medication forever?
Not necessarily. Some people control type 2 diabetes with lifestyle alone, some reduce medications after significant weight loss, and others need medication—including insulin—long term as the disease progresses. None of that reflects personal failure; it reflects biology. The right regimen is the one that keeps you safe and healthy, decided with your clinician over time. Do not adjust or stop medicines on your own.
Living Well With Type 2 Diabetes
A type 2 diabetes diagnosis is not a verdict—it’s a management challenge that millions of people navigate successfully every day. The key is consistency. Take your medications as prescribed, monitor as recommended, stay physically active, and make food choices that support stable glucose. Small, sustainable changes outperform dramatic overhauls you can’t maintain.
Build a healthcare team that works for you: a primary care provider or endocrinologist who stays current on diabetes care, a certified diabetes care and education specialist, a registered dietitian, and an eye doctor for annual retinal exams. Don’t neglect your mental health—diabetes distress and burnout are common, and addressing them is part of comprehensive care.
Stay informed, advocate for yourself at appointments, and remember that the treatment landscape keeps improving. New medications, better continuous monitoring, and therapies targeting the underlying biology of insulin resistance continue to emerge. The tools available today are the best they have ever been—and they keep getting better.
This article is general education, not medical advice, and is not a substitute for care from a qualified clinician. Type 2 diabetes management is individualized and should be supervised by a doctor. Do not start, stop, or change any medication or insulin on your own, and do not use any dose you read online. Diabetic ketoacidosis, hyperosmolar hyperglycemic state, and severe low blood sugar are medical emergencies—call 911 or go to the nearest emergency room.
Sources
- Centers for Disease Control and Prevention (CDC), National Diabetes Statistics Report and Diabetes Basics – https://www.cdc.gov/diabetes/php/data-research/index.html
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), Type 2 Diabetes – https://www.niddk.nih.gov/health-information/diabetes/overview/what-is-diabetes/type-2-diabetes
- Mayo Clinic, Type 2 Diabetes – https://www.mayoclinic.org/diseases-conditions/type-2-diabetes/symptoms-causes/syc-20351193
- American Diabetes Association, Standards of Care in Diabetes – https://diabetes.org/
- NIDDK, Diabetes Prevention Program (DPP) – https://www.niddk.nih.gov/about-niddk/research-areas/diabetes/diabetes-prevention-program-dpp