Written by Alma Pantaloukas · Medically reviewed by the CircuFiber Scientific Advisory Board · Updated: October 28, 2026
The main difference between type 1 and type 2 diabetes is how insulin is affected: in type 1 diabetes the body makes little to no insulin, while in type 2 diabetes the body still makes insulin but does not use or respond to it well. Type 1 diabetes is an autoimmune disease that cannot currently be prevented and requires lifelong insulin. Type 2 diabetes develops over time and is strongly linked to lifestyle risk factors. Prediabetes is the stage before type 2 diabetes, when blood sugar is higher than normal but not yet high enough to be diagnosed as diabetes, and it can often be reversed with lifestyle changes.
Key Takeaways
- Diabetes is a condition that impairs the body's ability to produce or use insulin, a hormone that regulates blood sugar levels.
- Type 1 diabetes is an autoimmune disease in which the immune system destroys the insulin-producing beta cells of the pancreas. It has no current cure, and insulin is a lifelong requirement.
- Type 2 diabetes develops over time as the body becomes resistant to insulin. Some people manage it with healthy eating and exercise; others also need medication or insulin.
- Prediabetes means blood sugar is higher than usual but not high enough to be diagnosed as diabetes. More than 1 in 3 American adults have it, and more than 80% do not know it.
- Prediabetes and type 2 diabetes can often be prevented or delayed with weight loss of 5 to 10% if overweight, a fiber-rich diet, regular physical activity, less alcohol, and not smoking. Type 1 diabetes cannot be prevented this way.
What is the difference between type 1 and type 2 diabetes?
Type 1 diabetes is an autoimmune condition in which the pancreas produces little to no insulin, while type 2 diabetes is a condition in which the pancreas still produces insulin but the body does not use or respond to it well. Both cause high blood sugar, but they start differently, appear at different ages, and are managed differently.
Diabetes is a condition that impairs the body's ability to produce or use insulin, a hormone that regulates blood sugar levels. However, there is good news: diabetes is a manageable condition and in some instances (except for type 1 diabetes) can be prevented with simple lifestyle modifications. Moreover, it is important to understand the difference between prediabetes, type 1, and type 2 diabetes so you can know the best way to care for your health.
Type 1 and type 2 are the two main types of diabetes. Other forms exist, including gestational diabetes (diabetes during pregnancy) and rarer genetic forms such as MODY diabetes.
What is type 1 diabetes?
Type 1 diabetes (T1D) is an organ-specific autoimmune disease in which the immune system attacks and destroys insulin-producing beta cells in the pancreas. This causes the pancreas to produce little to no insulin.
T1D typically shows up in the early stages of life, and given that there is no current cure for it, insulin intake is a lifelong requirement. It can, however, be diagnosed at any age. For warning signs in kids, see our guide to childhood diabetes symptoms and early detection.
What causes type 1 diabetes?
The cause of type 1 diabetes (T1D) is not known, but those with a family history seem to be at a higher risk. It is not caused by diet or lifestyle.
How is type 1 diabetes managed?
Type 1 diabetes is managed with insulin every day, together with regular blood sugar monitoring and attention to diet. Some studies suggest that adopting a low-carbohydrate diet can help individuals better manage blood glucose levels, especially when replacing refined carbohydrates with fiber-containing carbohydrates in the diet. Talk to your doctor or diabetes care team before changing how you eat, because carbohydrate intake and insulin doses need to be adjusted together.
What is type 2 diabetes?
Type 2 diabetes (T2D) is a form of diabetes in which the body still produces insulin but does not use or respond well to it, a problem called insulin resistance. Type 2 diabetes is primarily lifestyle-related and develops over time. It is by far the most common type of diabetes.
How is type 2 diabetes managed?
Type 2 diabetes is managed with a combination of lifestyle changes and, for many people, medication. While some people with T2D can control their blood sugar levels with healthy eating and exercise, others may require medication or insulin to manage it. Regular checks are part of every plan; see our tips for blood sugar monitoring.
What are the risk factors for type 2 diabetes?
The main risk factors for type 2 diabetes are excess weight, family history, age, inactivity, and having prediabetes. Risk factors for T2D include:
- Being overweight or obese
- Having a family history of type 2 diabetes
- 45 years or older
- Lack of physical activity (less than three times per week)
- Having a history of gestational diabetes (diabetes during pregnancy)
- Being African American, Hispanic or Latino, American Indian, or Alaska Native
- Having prediabetes
Not sure whether you have symptoms? Read about the nine signs of type 2 diabetes.
What is prediabetes?
Prediabetes is a condition in which blood sugar levels are higher than usual but not high enough to be diagnosed as diabetes. Prediabetes happens when the cells in the body stop responding to insulin as they should, causing the pancreas to increase insulin production. Eventually, the pancreas can’t keep up, so blood sugar levels rise.
Prediabetes is often a result of lifestyle choices such as a poor diet and lack of physical activity. It is estimated by the CDC that more than 1 in 3 Americans have prediabetes, with more than 80% unaware of their condition (see why most prediabetics are unaware of their condition).
Those with prediabetes are at a higher risk of developing type 2 diabetes, heart disease, and stroke. Prediabetes usually has no clear symptoms, which is why testing matters; learn more about prediabetes symptoms, diagnosis, and treatment.
How do prediabetes, type 1 diabetes and type 2 diabetes compare?
Prediabetes, type 1 diabetes and type 2 diabetes differ in what happens to insulin, who they affect, whether they can be prevented, and how they are managed. The table below compares them side by side.
| Prediabetes | Type 1 diabetes | Type 2 diabetes | |
|---|---|---|---|
| What happens to insulin | Cells stop responding to insulin as they should; the pancreas makes extra insulin to compensate | The immune system destroys insulin-producing beta cells; little to no insulin is made | The body still makes insulin but does not use or respond well to it (insulin resistance) |
| Blood sugar | Higher than usual, but below the diabetes range | High; rises quickly without insulin | High; usually rises gradually over years |
| Typical onset | Adults, often unnoticed for years | Typically early in life, but possible at any age | Usually adults, often 45 or older |
| Main causes and risk factors | Poor diet, lack of physical activity, excess weight | Autoimmune; cause unknown; family history raises risk | Excess weight, inactivity, family history, age, prediabetes, gestational diabetes |
| Can it be prevented? | Often, with lifestyle changes | No | Often prevented or delayed with lifestyle changes |
| How it is managed | Weight loss, diet, physical activity, regular testing | Lifelong insulin, blood sugar monitoring, diet | Healthy eating and exercise; medication or insulin for some people |
Doctors confirm which type a person has with blood tests; read more about diagnosing type 1 versus type 2.
How can you prevent prediabetes and type 2 diabetes?
Prediabetes and type 2 diabetes can often be prevented or delayed with lifestyle changes; type 1 diabetes cannot. The good news is that there are ways to prevent prediabetes and T2D:
- Maintaining healthy body weight and waist circumference
- If overweight or obese, aim to lose 5 to 10% of your current body weight
- Adopting a nutrient-dense and plant-predominant, fiber-rich diet
- Getting regular physical activity to meet the Physical Activity Guidelines for Americans
- 150 to 300 minutes per week of moderate-intensity physical activity, OR
- 75 to 150 minutes of vigorous-intensity aerobic physical activity
- Reduce alcohol consumption
- Quit smoking
Even small changes can have a significant impact on delaying or preventing diabetes. From adopting healthier eating habits, maintaining a healthy weight, and exercising regularly, lifestyle modifications are easy, inexpensive, and effective strategies to prevent the disease. For a step-by-step plan, see how to prevent type 2 diabetes and our guide to exercise for prediabetes.
How can you live well with type 1 or type 2 diabetes?
People with type 1 or type 2 diabetes can live full, healthy lives by managing blood sugar and caring for their bodies every day. It is essential for individuals not to let their diagnosis prevent them from living a normal, happy, and healthy life. Those living with diabetes can improve their quality of life by knowing how to properly care for their bodies and manage blood sugar levels, including regular foot care.
Diabetes can cause physical discomforts, such as pain, swelling, and foot sensitivity, so a daily foot check is part of good self-care; see ways to care for diabetic feet. Work with a healthcare professional to make a plan that works for your lifestyle.
When should you see a doctor about prediabetes or diabetes?
See a doctor and ask for a blood sugar test if you have risk factors for type 2 diabetes, such as being 45 or older, being overweight, or having a family history of diabetes, even if you feel fine, because prediabetes usually has no symptoms. See a doctor promptly if you notice increased thirst, frequent urination, unexplained weight loss, fatigue, blurred vision, or slow-healing cuts. Seek urgent care if these symptoms come on quickly with nausea, vomiting, stomach pain, or confusion, which can be signs of a diabetes emergency.
Frequently asked questions about type 1 vs type 2 diabetes
Which is worse, type 1 or type 2 diabetes?
Neither type is simply "worse"; both are serious and both can lead to complications if blood sugar stays high. Type 1 diabetes requires insulin from diagnosis onward, while type 2 diabetes often progresses slowly and may be managed with lifestyle changes and medication at first. With good management, people with either type can lower their risk of complications.
Can type 1 diabetes turn into type 2 diabetes?
No. Type 1 diabetes is an autoimmune disease and does not turn into type 2 diabetes. A person with type 1 diabetes can, however, also develop insulin resistance. Read more on whether type 1 turns into type 2.
Are the symptoms of type 1 and type 2 diabetes different?
The symptoms of type 1 and type 2 diabetes are similar, including thirst, frequent urination, fatigue, and blurred vision. The difference is speed: type 1 symptoms often appear quickly, over weeks, while type 2 symptoms tend to develop slowly and may go unnoticed for years.
What is the difference between prediabetes and type 2 diabetes?
Prediabetes means blood sugar is higher than usual but not high enough to be diagnosed as diabetes; type 2 diabetes means it has crossed that threshold. Prediabetes raises the risk of developing type 2 diabetes, heart disease, and stroke, but it can often be reversed with weight loss, a healthy diet, and regular physical activity.
Can type 2 diabetes be prevented if you have prediabetes?
Often, yes. Losing 5 to 10% of body weight if you are overweight, eating a fiber-rich, plant-predominant diet, and getting 150 to 300 minutes of moderate activity a week can delay or prevent type 2 diabetes. Talk to your doctor about how often to retest your blood sugar.
References, studies and sources
- Centers for Disease Control and Prevention (CDC). Prevalence of Prediabetes Among Adults, National Diabetes Statistics Report. https://www.cdc.gov/diabetes/data/statistics-report/prevalence-of-prediabetes.html
- U.S. Department of Health and Human Services. Physical Activity Guidelines for Americans, 2nd edition. https://health.gov/sites/default/files/2019-09/Physical_Activity_Guidelines_2nd_edition.pdf
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Diabetes. https://www.niddk.nih.gov/health-information/diabetes
- American Diabetes Association. https://diabetes.org/
- Centers for Disease Control and Prevention (CDC). Diabetes. https://www.cdc.gov/diabetes/
Healthcare disclaimer: Always consult your physician before beginning any program. This general information is not intended to diagnose any medical condition or to replace your healthcare professional. If you experience any pain or difficulty, stop and consult your healthcare provider. CircuFiber socks are a general wellness product intended to promote a temporary increase in local blood flow and circulation; they are not intended to diagnose, treat, cure, or prevent any disease. Individual results vary.
