What Is Diabetes? The Many Types of Diabetes, Explained
Health ConditionsDiabetes

Every Type of Diabetes, Explained

Every Type of Diabetes, Explained
Everyday Health
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Updated on December 11, 2025
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Diabetes is not just one disease. It’s a large family of health conditions that are all defined by hyperglycemia (high blood sugar).

There are several forms of diabetes, some very rare, and others extremely common. But every type involves some kind of dysfunction in the use or production of insulin, a hormone made in the pancreas that allows the body to use sugar in the bloodstream for energy. When blood sugar levels get too high, it causes damage to blood vessels and nerves throughout the body, which is why different forms of diabetes tend to have similar symptoms and complications, such as problems with eyesight, feet, and kidneys.

There is no cure for diabetes, and some forms of the disease are lifelong, but all can be treated and managed with diet, exercise, and medication.

Type
Description
Type 1 Diabetes
An autoimmune disease in which the pancreas produces little or no insulin, leading to high blood sugar levels that require daily insulin treatment
Type 2 Diabetes
A chronic condition characterized by insulin resistance, often caused by a combination of genetic factors, obesity, and a lack of physical activity
Gestational Diabetes
A condition in which high blood sugar levels are first diagnosed during pregnancy, resulting from placental hormones causing insulin resistance, which usually resolves after the baby is born
LADA / Type 1.5
A slow progressive autoimmune form of diabetes diagnosed in adulthood that leads to eventual insulin dependence, often after an initial misdiagnosis as type 2 diabetes
Monogenic Diabetes
A rare, inherited form of diabetes caused by a mutation in a single gene, most often diagnosed in younger people
Type 3c Diabetes
A form of diabetes caused by damage to the pancreas, which impairs its ability to produce both insulin and digestive enzymes.
Drug-Induced Diabetes
A form of diabetes caused by the use of certain medications, such as glucocorticoids, sometimes reversible upon discontinuing the offending drug
Prediabetes
A condition in which blood sugar levels are higher than normal but not yet high enough for a type 2 diabetes diagnosis, indicating insulin resistance and a significantly increased risk of diabetes.
“Type 3 Diabetes”
An unofficial term used to describe Alzheimer's disease, based on the theory that it is caused by chronic insulin resistance that occurs specifically in the brain.
Diabetes Insipidus
A rare condition, now known as arginine vasopressin deficiency or resistance, that is unrelated to other forms of diabetes. The body cannot properly regulate fluid balance, resulting in excessively large amounts of dilute urine and unquenchable thirst

Diabetes 101: What Are the Different Types of Diabetes?

Diabetes 101: What Are the Different Types of Diabetes?

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Type 1 Diabetes

Type 1 diabetes is an autoimmune disorder in which a person’s immune system attacks and destroys the cells in the pancreas that make insulin. As natural insulin production declines, blood glucose can rise to life-threatening levels. The symptoms of type 1 diabetes can come on very quickly, especially in the young. Sometimes the condition isn’t identified until a patient has experienced a deadly condition called diabetic ketoacidosis (DKA).

People with type 1 diabetes must take insulin every day to replace the insulin their bodies don’t make, as well as monitor their blood glucose levels daily.

Type 1 diabetes affects about 5.7 percent of adults ages 20 and older with diagnosed diabetes in the United States.

This form of diabetes can occur at any age, contrary to outdated beliefs that it only develops during childhood. In fact, more than 50 percent of new type 1 diabetes cases are diagnosed in adults.

Type 1 diabetes is a lifelong chronic condition without a cure.

 If they’re diligent about taking insulin and monitoring their blood glucose levels every day, a person with type 1 diabetes can live a full life. Advancements in insulin, insulin delivery technology, and blood glucose monitoring have significantly improved the quality of life of people with type 1 diabetes and their ability to maintain healthy blood glucose levels.

Despite these advancements, people with type 1 diabetes still face daily risks of hypoglycemia (low blood sugar), and blood sugar management can be a demanding balancing act.

Type 2 Diabetes

Type 2 diabetes results from insulin resistance, an inability to use the hormone insulin properly. As the body’s demand for insulin increases, the pancreas may struggle to produce enough of the hormone to maintain healthy blood glucose levels.

The condition typically develops in people older than 45, but the incidence of type 2 diabetes in children is on the rise.

Type 2 diabetes has a strong genetic component, but it can also be triggered by modifiable risk factors such as excess weight and a sedentary lifestyle.

There isn’t a cure for type 2 diabetes, but some people can put the condition into remission through diet, exercise habits, and weight loss.

 For most others, type 2 diabetes is a progressive disease, and the condition will worsen over time. It is typical to require more medication as you age.
Treatment options for type 2 diabetes vary based on your blood glucose and A1C levels but can include weight loss, lifestyle changes, medication, and bariatric surgery for those who also have obesity. Though type 2 diabetes may only have subtle symptoms at first, it can eventually lead to debilitating complications, such as kidney disease, neuropathy, amputation, vision loss, and cardiovascular disease. Keeping your blood sugar within your target range and taking medications as prescribed will greatly reduce the risk of these bad outcomes.

 

Gestational Diabetes

Pregnant women develop gestational diabetes during about 14 percent of all pregnancies in the United States. To help ensure there’s enough glucose available to provide energy for a growing fetus, pregnant women normally develop a certain amount of insulin resistance, and sometimes this causes blood sugar to increase to the diabetic range.

Typically, treatment for gestational diabetes focuses on diet and lifestyle changes, but sometimes doctors prescribe oral diabetes medications or insulin to keep blood sugar in a healthy range.

Gestational diabetes can lead to complications that affect the health of both the mother and child. Women with gestational diabetes have a higher risk of preeclampsia, and their infants are more likely to be born prematurely or have a higher than normal birth weight, creating complications during delivery. The infants can also go on to develop dangerously low blood sugar levels soon after birth. Later in life, they have an increased risk of developing obesity, heart disease, and type 2 diabetes.

Gestational diabetes usually goes away after the child is born, but half of all women with the condition go on to develop type 2 diabetes within a few years of their pregnancy.

Latent Autoimmune Diabetes in Adults (LADA, or Type 1.5 Diabetes)

Latent autoimmune diabetes in adults (LADA) is a subtype of type 1 diabetes that develops very slowly during adulthood. It’s often mistaken for and misdiagnosed as type 2 diabetes.

People with LADA may not need insulin for years. Instead, lifestyle changes and medications for type 2 diabetes, such as metformin or GLP-1s, may temporarily keep blood glucose levels in a healthy range.

As their natural insulin production declines, people with LADA tend to find that these early treatment methods are no longer effective. Ultimately, they will likely need daily insulin therapy.

Generally, doctors diagnose LADA by testing for the presence of antibodies to pancreatic cells and C-peptide levels, which indicate how much insulin the pancreas is producing. In people with LADA, autoantibodies are identifiable and C-peptide levels are low.

People with LADA eventually need to follow guidelines pertaining to type 1 diabetes for ongoing management.

Monogenic Diabetes

Monogenic diabetes is a family of rare genetic conditions that arise from a mutation on a single gene. These conditions are usually diagnosed in young people (25 or younger) and often run in families.

MODY

The best known form of monogenic diabetes is maturity-onset diabetes of the young (MODY). This condition is distinct from types 1 and 2 diabetes, and doesn’t involve autoimmunity or insulin resistance, but can be misdiagnosed as either. MODY typically does not require insulin and is usually managed with other glucose-lowering drugs such as sulfonylureas, though the precise treatment of MODY will differ depending on which gene is affected.

    If a parent has MODY, their child has a 50 percent risk of developing the condition. Genetic testing is key to obtaining an accurate diagnosis.

    Neonatal Diabetes

    Neonatal diabetes is a rare form of monogenic diabetes that develops within the first six months of a child's life. Unlike type 1 diabetes, it’s not caused by the immune system. An accurate neonatal diabetes diagnosis requires genetic testing.

    Neonatal diabetes can be transient, which means it can resolve by itself, though it may possibly return later in life. It can also be permanent, requiring daily insulin therapy indefinitely.

    Signs and symptoms of neonatal diabetes include inadequate weight gain, dehydration, and high blood sugar. The earlier neonatal diabetes is diagnosed, the more likely long-term complications can be prevented.

      Type 3c Diabetes

      Type 3c diabetes, also known as pancreatogenic or pancreatic diabetes, is caused by direct damage to the pancreas. This damage can be caused by conditions such as chronic pancreatitis or cystic fibrosis, or by surgical removal of the pancreas (pancreatectomy).

      People with type 3c diabetes may also experience exocrine pancreatic insufficiency (EPI), an inability to produce normal amounts of digestive enzymes. Managing type 3c diabetes depends on the scale of damage to the pancreas, and can include any combination of non-insulin diabetes medications, insulin therapy, and pancreatic enzyme supplementation.

      Drug-Induced Diabetes

      A number of drugs can precipitate the development of diabetes by causing weight gain, insulin resistance, and similar side effects. In some cases, ceasing to use the offending drug can resolve drug-induced diabetes, but in others it is a permanent condition that will need to be treated similarly to type 2 diabetes.

      Steroid-induced diabetes is a form of diabetes caused by the use of glucocorticoids like prednisone. These medications are powerful anti-inflammatory drugs, but they can increase blood glucose levels as a side effect. It’s possible to develop diabetes as a result of taking corticosteroids, but this will generally only happen to people who are already on track to develop diabetes in the future.

      Post-transplantation diabetes mellitus (PTDM) is a common complication of solid organ transplants, including heart, liver, lung, and especially kidney transplants. Transplant recipients require a number of medications to prevent organ rejection, and many of these, including steroids and immunosuppressants, can raise blood sugar levels. Treatment is similar to that of type 2 diabetes, with the added complication of a continuing need for post-transplant medical treatment.

      Other drugs that have been implicated in the development of diabetes include antipsychotic drugs, statins, antiretrovirals for HIV treatment, and chemotherapy for cancer treatment.

      Prediabetes

      Prediabetes is not technically a form of diabetes, but it can lead to type 2 diabetes.

      Almost 98 million adults in the United States have prediabetes, affecting 38 percent of the population. It’s experienced by nearly half of all adults older than 65.

      Prediabetes exists on a continuum with type 2 diabetes, and shares the same causes. Family history, advancing age, excess weight, and a sedentary lifestyle are among the known risk factors.

      Prediabetes itself doesn’t typically lead to diabetes-related complications because blood glucose levels aren’t high enough to cause significant damage to nerves and blood vessels throughout the body. But a person with prediabetes has up to a 50 percent chance of developing type 2 diabetes within 10 years.

       When prediabetes progresses to type 2 diabetes, your healthcare team may recommend using medication to lower your blood sugar.
      Not everyone with prediabetes will develop type 2 diabetes, and with intervention some people can reverse prediabetes. A weight loss of just 7 percent of your body weight (15 pounds if you weigh 200 pounds) may lower your risk of type 2 diabetes by 58 percent.

      No drugs are approved in the United States for the specific treatment of prediabetes, but some doctors will prescribe the diabetes drug metformin off-label,

       and recent research suggests GLP-1 and dual GLP-1/GIP receptor agonist medications like semaglutide and tirzepatide can help some people with prediabetes reverse the condition.

       

      ‘Type 3 Diabetes’

      Unlike the other types of diabetes mentioned, so-called “type 3 diabetes” isn’t an official diagnosis recognized by the medical community. Instead, it’s a research term referring to evidence that Alzheimer’s disease and other neurodegenerative conditions are linked to insulin resistance in the brain.

      Diabetes may disrupt blood flow or create abnormal protein accumulations that lead to brain cell death and conditions such as cognitive impairment, dementia, Parkinson’s disease, and Alzheimer’s disease.

      Diabetes Insipidus (Arginine Vasopressin Disorders)

      Diabetes insipidus (DI) is not related to other forms of diabetes mellitus, and has nothing to do with insulin or blood sugar control. This is a rare condition with a variety of potential causes, such a pituitary tumor, traumatic brain injury, or certain medications, that inhibits the body’s ability to retain water. People with DI produce more urine than normal, often colorless and odorless, and may experience constant thirst.

      To avoid confusion, this condition was officially renamed in 2022, and is now known as arginine vasopressin deficiency or arginine vasopressin resistance.

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      Diagnosis (and Misdiagnosis)

      It is often easy for clinicians to diagnose the presence of diabetes simply by measuring your blood sugar level. Sometimes your diabetes status can be assessed by a clinician almost immediately, with a single rapid blood sugar or A1C test. In other cases, you may need to take multiple tests, such as an oral glucose tolerance test (OGTT), which reveals how your body responds to a sugary drink.

      Determining the type of diabetes you have may require additional testing if doctors are unsure if you have type 1 diabetes, type 2 diabetes, or a different form. Some special tests that can refine your diagnosis include:

      • Autoantibody Tests These tests, which look for antibodies targeting insulin or certain pancreatic cells, are conducted most often to diagnose type 1 diabetes or LADA.

      • C-Peptide Test This test measures the amount of C-peptide, a protein that mirrors the level of insulin in the body, low levels of which can indicate type 1 diabetes or LADA.

      • Genetic Testing MODY and neonatal diabetes may be detected using genetic testing.

      Sometimes these additional tests are administered years after an initial diabetes diagnosis, especially when treatment has proved ineffective. Misdiagnosis is not uncommon: Some 40 percent of adults with type 1 diabetes are initially misdiagnosed with type 2 diabetes, for example.

       Misdiagnosis is less frequent in children, but may still occur up to 6 percent of the time.

      If you’re unsure that you’ve been diagnosed with the right type of diabetes, ask your doctor or endocrinologist what additional tests are available. Finding the right diagnosis can help you get the right treatment and improve your long-term health.

      Symptoms and Complications of Diabetes

      Many symptoms overlap between different types of diabetes, because they are all fundamentally caused by high blood sugar. Symptoms of undiagnosed diabetes may include:

      • Increased thirst
      • Increased hunger
      • Frequent urination
      • Unexplained weight loss
      • Fatigue
      • Blurred vision
      • Numbness or tingling in the hands or feet
      • Sores or cuts that heal slowly or not at all
      • Frequent infections
      Illustrative graphic titled Signs and Symptoms of Diabetes Call-outs: Increased Thirst Frequent Urination Blurred Vision Increased Hunger Fatigue Numbness or Tingling in Hands or Feet Slow-Healing Sores or Cuts Frequent Infections Unexplained Weight Loss
      Everyday Health
      Different forms of diabetes also tend to cause similar types of complications, which can range from uncomfortable to life-threatening. Major long-term complications of diabetes, which may not emerge for years, include:

      Other potential long-term complications of diabetes include:

      Diabetes can also create a number of short-term dangers:

      • Hypoglycemia (low blood glucose) is a risk for anyone taking insulin or non-insulin medications like sulfonylureas. Left untreated, hypoglycemia can lead to lightheadedness, confusion, diabetic seizure, and even death.
      • Diabetic ketoacidosis (DKA) occurs when the body doesn’t have enough insulin to convert glucose into energy. It begins to break down fat for fuel, producing ketones at toxic levels. Left untreated, it can lead to seizures, coma, and death. DKA is most common in people with type 1 diabetes.
      • Hyperglycemic hyperosmolar nonketotic syndrome is an emergency caused by chronically high blood glucose levels. It’s most common in people with type 2 diabetes.

      Prognosis and Outlook of Diabetes

      It is impossible to generalize about the impact that diabetes can have on your lifespan or quality of life, as your prognosis will vary depending on the type, your management of the condition, and your overall health. While some forms of diabetes are lifelong conditions, you can live a full life with any type of diabetes.

      Type 1 diabetes, LADA, and MODY are lifelong conditions that may require daily attention, frequent medication adjustments, and thoughtful lifestyle habits. If you require daily insulin therapy, your management will probably involve a significant learning curve. But the tools used to manage diabetes have improved massively in recent decades, with superior forms of insulin and management technology allowing people with the condition to live longer lives.

      Type 2 diabetes is usually a lifelong condition. In some cases, this is a progressive illness that requires more intense treatment with age. But with self-care, people with type 2 diabetes can live very full, active, and healthy lives, and may not necessarily experience significant complications or loss of lifespan.

       A small percentage of people with type 2 diabetes will even achieve diabetes remission: normal blood sugar levels without the use of medication. This usually requires diligent lifestyle changes and weight loss. The same healthy changes can also help to reverse prediabetes.

      Gestational diabetes usually goes away after the baby is born and the women’s hormone levels normalize. But lifestyle factors can increase the risk of type 2 diabetes later in life for someone with a history of gestational diabetes.

      The Takeaway

      • There are several types of diabetes, each of which involves high blood glucose levels and is caused by some form of insulin dysfunction.
      • The symptoms of diabetes are generally similar, regardless of diabetes type, because they are all caused by high blood sugar.
      • Diagnosing the presence of diabetes is often straightforward, but determining the type of diabetes is sometimes trickier, and it will take some people years to learn exactly what condition they have.
      • There is no cure for diabetes, but with proper treatment most conditions in the diabetes family won't significantly reduce your long-term health or quality of life.

      FAQ

      Does sugar cause diabetes?
      Not exactly. An unhealthy diet is a risk factor for some forms of diabetes, but every type of diabetes involves dysfunction in the way the body handles the sugar you consume. 
      Common signs of hyperglycemia (high blood sugar) can include excessive thirst, blurred vision, headache, frequent urination, and fatigue. If you experience these symptoms, reach out to your healthcare provider.
      Both are conditions with life-altering symptoms and complications. Type 2 diabetes is caused by insulin resistance, whereas type 1 diabetes is the result of an autoimmune disorder in which a person’s own immune system attacks and destroys their insulin-making cells.
      Family history is a risk factor for many forms of diabetes, though some, particularly type 2 diabetes, are also related to lifestyle choices.
      Dietary recommendations are generally similar for different types of diabetes. Try to limit your intake of saturated fats and of processed foods high in sugar and refined starches.

      Resources We Trust

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      Everyday Health follows strict sourcing guidelines to ensure the accuracy of its content, outlined in our editorial policy. We use only trustworthy sources, including peer-reviewed studies, board-certified medical experts, patients with lived experience, and information from top institutions.
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      Anna L. Goldman, MD

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      Anna L. Goldman, MD, is a board-certified endocrinologist. She teaches first year medical students at Harvard Medical School and practices general endocrinology in Boston.

      Dr. Goldman attended college at Wesleyan University and then completed her residency at Icahn School of Medicine at Mount Sinai Hospital in New York City, where she was also a chief resident. She moved to Boston to do her fellowship in endocrinology at Brigham and Women's Hospital. She joined the faculty after graduation and served as the associate program director for the fellowship program for a number of years.

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      Ginger Vieira has lived with type 1 diabetes and celiac disease since 1999, and fibromyalgia since 2014. She is the author of Pregnancy with Type 1 Diabetes, Dealing with Diabetes Burnout, Emotional Eating with Diabetes, and Your Diabetes Science Experiment.

      Ginger is a freelance writer and editor with a bachelor's degree in professional writing, and a background in cognitive coaching, video blogging, record-setting competitive powerlifting, personal training, Ashtanga yoga, and motivational speaking.

      She lives in Vermont with a handsome husband, two daughters, and a loyal dog named Pedro.

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      Ross Wollen joined Everyday Health in 2021 and now works as a senior editor, often focusing on diabetes, obesity, heart health, and metabolic health. He previously spent over a decade as a chef and craft butcher in the San Francisco Bay Area. After he was diagnosed with type 1 diabetes at age 36, he quickly became an active member of the online diabetes community, eventually becoming the lead writer and editor of two diabetes websites, A Sweet Life and Diabetes Daily. Wollen now lives with his wife and children in Maine's Midcoast region.

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