Illustration of Type 1 Diabetes

What Is Type 1 Diabetes?

Type 1 diabetes is a chronic condition that occurs when the pancreas makes little to no insulin, which causes high blood sugar.

Type 1 diabetes is a chronic condition that occurs when your pancreas doesn't make enough insulin. Your pancreas is the digestive organ behind your stomach that helps your body turn food into fuel. Insulin is a hormone that helps move glucose (sugar) from your blood and into your cells to give you energy.

If your body doesn't make enough insulin, glucose piles up in your bloodstream. High blood sugar levels can damage your heart, blood vessels, nerves, kidneys, eyes, feet, and skin if left untreated. Extremely high blood sugar levels can also lead to diabetic ketoacidosis (DKA)—a life-threatening condition that causes your blood to become acidic.

Type 1 diabetes is one type of diabetes mellitus (diabetes) and makes up about five percent of all diabetes cases. While the cause of type 1 diabetes is unknown, researchers do know that a mix of genetic and environmental triggers can disrupt proper functioning of the pancreas.

Previously known as juvenile diabetes, type 1 diabetes commonly develops in children and adolescents. However, you can develop this condition at any age. If you receive a type 1 diabetes diagnosis, you may experience symptoms such as excessive thirst, weakness, fatigue, and unexpected weight loss.

Currently, there is no cure for type 1 diabetes. But you can manage your condition and keep your blood sugar under control with insulin therapy and a healthy lifestyle.

On November 17, 2022, the Food and Drug Adminstration (FDA) approved a drug called "Tzield" to help delay the progression of type 1 diabetes in people over the age of 8. Tzield comes in the form of an injectable vaccine that can slow or prevent your immune system from attacking healthy cells in the pancreas.


There are three subtypes of type 1 diabetes: Acute-onset (AT1D), slowly progressive (SP1D), and fulminant (FT1D).

Acute-Onset Type 1 Diabetes (AT1D)

People with AT1D suddenly begin to experience symptoms because they develop a complication known as diabetic ketoacidosis (DKA). DKA can occur if your body produces too many ketones, which are acids produced by the liver. Usually, your liver makes too many ketones if your body doesn't have enough insulin to transfer glucose (sugar) to your cells.

People with AT1D develop DKA less than three months after having symptoms of hyperglycemia, which is the clinical term for high blood sugar. Symptoms may include being extremely thirsty, losing weight unintentionally, and having to use the bathroom more often. Most people with type 1 diabetes have this subtype.

Slowly Progressive Type 1 Diabetes (SP1D)

Unlike acute-onset type 1 diabetes, SP1D gradually develops over time. People with SP1D have antibodies that destroy the cells in your pancreas that produce insulin.

SP1D can develop in children or adults. Because symptoms can take longer to develop with this subtype, it is common for people to develop this condition later in life. 

Fulminant Type 1 Diabetes (FT1D)

FT1D is a rare subtype of type 1 diabetes. Symptoms of FT1D can develop very quickly. If you have FT1d, the antibodies in your immune system rapidly destroy the cells in the pancreas that make insulin, making symptoms hard to manage.

This condition can have serious complication and may be fatal if untreated.


If your pancreas isn't producing the right amount of insulin, symptoms can arise suddenly. Typically, those symptoms include:

  • Frequent urination: When excess sugar builds up in your bloodstream, your kidneys may try to reduce the sugar by giving you the urge to pee. You may often feel the need to wake up in the middle of the night to use the bathroom. If you have a child with type 1 diabetes, you may notice they are wetting the bed more often.
  • Excessive thirst: As your kidneys try to flush out urine or other excess fluids, you can become dehydrated. Your body responds to dehydration by making you feel thirsty.
  • Increased hunger: If insulin cannot drive blood sugar into cells, you may have a hard time getting energy from the food you eat. A lack of energy may make you feel more hungry.
  • Unintended weight loss: Because your body isn't using energy or sugar from the food that you are eating, it resorts to using your body's fat or muscle as a source of energy. In doing so, you may notice that you are losing weight without trying.
  • Fatigue: Even if you are getting enough sleep, you may feel tired throughout the day because your body isn't receiving energy from the food you eat.
  • Tingling and numbness in the limbs: High blood sugar levels cause nerve damage. As a result, you may start to feel a pins and needles sensation in your hands and feet.
  • Sores or wounds that heal slowly: Diabetes affects the immune system. That may impair how your immune system is able to fight infections and heal wounds.
  • Blurry eyesight: High blood sugar may damage the tiny blood vessels that give blood to your retina, the part of your eye that helps you see clearly.

Some people with type 1 diabetes develop diabetic ketoacidosis (DKA). That happens if their blood sugar is very high. Symptoms of DKA include:

  • Trouble breathing
  • Dry and flushed skin
  • Breath that smells fruity 
  • Nausea and vomiting
  • Stomach cramps

Diabetic ketoacidosis (DKA) is a life-threatening medical emergency that must be treated right away. If you or a loved one is displaying symptoms of DKA, call your healthcare provider or 911 immediately.


The exact cause of type 1 diabetes is unknown. But, researchers know it's an autoimmune condition that affects the functioning of your pancreas.

When you have an autoimmune conditions, your body begins to attack healthy cells because your immune system mistakenly thinks that your cells are invading your body. In the case of type 1 diabetes, the body attacks beta cells in the pancreas.

A mix of genetic and environmental triggers may prompt the disease to develop. A family history of type 1 diabetes or having certain genes (e.g., HLA-DR gene) can increase your risk. Other factors that may also trigger trigger the onset of symptoms if you are at increased risk for developing the condition include:

  • Infections
  • Stress
  • Living in a cold climate
  • Not being breastfed as a baby


A healthcare provider can diagnose type 1 diabetes using several methods. The following tests check for a general diabetes diagnosis.

  • A1C test: This is a type of hemoglobin test that measures your blood sugar in the past three months before you take the test. You do not need to fast or change your diet before an A1C test. An A1C greater than or equal to 6.5% indicates you have diabetes.
  • Fasting plasma glucose (FPG) test: This test that measures your blood sugar. Before an FPG test, you will need to fast for at least eight hours. Generally, people usually fast overnight and have their blood drawn in the morning. A fasting blood sugar level greater than or equal to 126 milligrams per deciliter of blood means that you have diabetes. An FPG test should be repeated to confirm the original test, as blood sugar can fluctuate.
  • Oral glucose tolerance test (OGTT): This blood exam tests your blood sugar levels over the span of two hours. First, a healthcare provider will draw your blood. Then, they'll ask you to consume a sugary drink. They will repeatedly draw your blood over the next two hours to measure how your body stores or uses the sugar. A blood sugar level greater than or equal to 200 milligrams per deciliter of blood can determine diabetes.
  • Random glucose test: This test assesses your blood sugar level at any time. Similar to the OGTT, a blood sugar level greater than or equal to 200 milligrams per deciliter of blood may lead to a diabetes diagnosis. A random glucose test should be done twice to confirm a diagnosis.
  • Glucose challenge test: Healthcare providers may give this test to pregnant people. First, you will consume a sugary drink. One hour later, the healthcare provider will take a blood sample. If your blood sugar level exceeds 135 milligrams per deciliter of blood, they will likely give you an OGTT. A diabetes diagnosis can be made based on the results of the OGTT.

Your healthcare provider will use additional blood testing to learn whether you have type 1 or type 2 diabetes. Type 1 diabetes diagnostic tests primarily look for autoantibodies, or proteins in the immune system that mistakenly attack the cells that create insulin. Some tests that check for type 1 diabetes autoantibodies are:

  • Insulin autoantibodies (IAA)
  • Insulinoma-associated-2 autoantibodies (IA-2A)
  • Islet cell cytoplasmic autoantibodies (ICA)
  • Glutamic acid decarboxylase autoantibodies (GADA or anti-GAD)

Autoantibody tests can also help determine what stage of type 1 diabetes you have.


There are three stages of type 1 diabetes, which include:

  • Stage 1: Your blood sugar is still in a healthy range and you are not experiencing symptoms. However, you have tested positive for two or more autoantibodies.
  • Stage 2: You have no symptoms, but your blood sugar is no longer in a healthy range. Like stage 1, you have tested positive for two or more autoantibodies and your immune system is producing cells that attack insulin in your body.
  • Stage 3: This is an official clinical diagnosis of type 1 diabetes. You have tested positive for multiple autoantibodies, blood sugar is high, and you are experiencing symptoms like excessive thirst and fatigue.


There is no known cure for type 1 diabetes. Instead, the goal of treatment for type 1 diabetes is to help you manage your condition. Keeping your blood sugar in a healthy range can help you improve symptoms and live a healthy life.

If you receive a type 1 diabetes diagnosis, your healthcare provider will ask you to regularly monitor your blood sugar. You will also need to give your body the insulin your pancreas is no longer making. It's important to take your insulin as instructed by your healthcare provider because missing insulin doses can lead to DKA.

How you receive insulin will be based on your age, severity of the condition, access to medication, lifestyle, and insurance. Some insulin options include injections, insulin pens, or insulin pumps. A newer type of technology known as a continuous glucose monitor (CGM) can also be connected to an insulin pump to check your blood sugar levels throughout the day and give your body insulin as needed.

When you get a diagnosis for type 1 diabetes, your healthcare provider may help you put together a diabetes care team to help you mange your condition and keep an eye out for complications to different body parts or organs. Your care team might include a(n):

Type of Provider Specialty
Primary care physician General care
Endocrinologist Hormones and medication management
Podiatrist Feet
Ophthalmologist Eyes 
Psychologist, psychiatrist, or social worker  Mental health
Neurologist Brain and nervous system
Pharmacist Medication
Registered dietician nutritionist (RDN) Diet and nutrition
Certified diabetes care and education specialist (CDCES) Disease management 


In November 2022, the U.S. Food and Drug Administration (FDA) approved a drug called "Tzield" that may delay a type 1 diabetes diagnosis in people who are at risk for the condition. Tzield is the first prevention drug to be approved and comes in the form of an injectable vaccine.

Clinical trials of Tzield showed that 45% of research participants taking the vaccine had an average delay of 50 months (4.16 years) before receiving a type 1 diabetes diagnosis. Tzield is currently approved for anyone over the age of 8 who is at an increased risk of developing type 1 diabetes.

More research on additional prevention methods are still ongoing. Future studies may help healthcare providers understand new ways to stop or slow damage the beta cells in your pancreas.

You can also prevent further damage of type 1 diabetes by keeping your blood sugar levels in a healthy range. Monitoring your blood sugar daily, taking your insulin doses on time, and getting exercise, good sleep, and healthy nutrition can improve disease management.

Living With Type 1 Diabetes

Living with type 1 diabetes can pose significant challenges. It's normal to feel frustrated.

Aside from regular check-ins with your care team and taking your insulin on time, a healthy lifestyle can further help you managing your blood sugar levels. Some ways to improve your overall lifestyle include:

  • Manage stress: High stress can increase blood sugar levels. Some activities that can help you manage stress include meditation, spending time with loved ones, or journaling.
  • Eat a healthy diet: Vegetables, fruits, complex carbohydrates, lean protein, and healthy fats can keep your blood sugar in a healthy range.
  • Exercise: Regular physical activity helps your muscles use sugar for energy.
  • Sleep well: Getting a good night's sleep can regulate your blood sugar levels.
  • Seek out social support: Staying in touch with your loved ones and other people who live with the condition can help you feel supported and lower your stress as you navigate life with type 1 diabetes.

A Quick Review

Type 1 diabetes happens when your pancreas does not produce enough insulin, which results in having high blood sugar. Symptoms of type 1 diabetes may include getting increasingly hungry or thirsty, feeling tired or weak, needing to use the bathroom more often, and losing weight without trying.

If you have symptoms, it is important to reach out to your healthcare provider to get tested and receive a proper diagnosis. Your healthcare provider and care team can set up a treatment plan that can help you manage your condition. Early treatment can prevent further damage to your heart, blood vessels, nerves, kidneys, eyes, feet, and skin. 

While type 1 diabetes does not have a cure, taking your insulin on time and making healthy lifestyle changes can help you manage your condition. 

Was this page helpful?
19 Sources uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. National Institute of Diabetes and Digestive and Kidney Diseases. Type 1 diabetes.

  2. Centers for Disease Control and Prevention. Prevalence of diagnosed diabetes.

  3. American Diabetes Association. Diabetes symptoms.

  4. National Library of Medicine. Type 1 diabetes.

  5. U.S. Food and Drug Administration. FDA approves first drug that can delay onset of type 1 diabetes.

  6. Kawasaki E, Maruyama T, Imagawa A, et al. Diagnostic criteria for acute-onset type 1 diabetes mellitus (2012): Report of the Committee of Japan Diabetes Society on the Research of Fulminant and Acute-onset Type 1 Diabetes MellitusJ Diabetes Investig. 2014;5(1):115-118. doi:10.1111/jdi.12119

  7. Centers for Disease Control and Prevention. Diabetic ketoacidosis.

  8. American Diabetes Association. Hyperglycemia.

  9. Nishimura A, Matsumura K, Kikuno S, et al. Slowly Progressive Type 1 Diabetes Mellitus: Current Knowledge And Future PerspectivesDiabetes Metab Syndr Obes. 2019;12:2461-2477. doi:10.2147/DMSO.S191007

  10. You W, Yang J, Liu Y, et al. Fulminant type 1 diabetes mellitus: Two case reportsMedicine (Baltimore). 2019;98(5):e14319. doi:10.1097/MD.0000000000014319

  11. Redondo MJ, Steck AK, Pugliese A. Genetics of type 1 diabetesPediatr Diabetes. 2018;19(3):346-353. doi:10.1111/pedi.12597

  12. Esposito S, Toni G, Tascini G, Santi E, Berioli MG, Principi N. Environmental Factors Associated With Type 1 DiabetesFront Endocrinol (Lausanne). 2019;10:592. doi:10.3389/fendo.2019.00592

  13. National Institute of Diabetes and Digestive and Kidney Diseases. Diabetes tests & diagnosis.

  14. American Diabetes Association Professional Practice Committee. Classification and diagnosis of diabetes: Standards of medical care in diabetes-2022. Diabetes Care. 2022;45(Suppl 1):S17-S38. doi:10.2337/dc22-S002

  15. National Institute of Diabetes and Digestive and Kidney Diseases. Insulin, medicines, & other diabetes treatments.

  16. Wiley J, Westbrook M, Long J, Greenfield JR, Day RO, Braithwaite J. Multidisciplinary diabetes team care: the experiences of young adults with Type 1 diabetesHealth Expect. 2015;18(5):1783-1796. doi:10.1111/hex.12170

  17. Beik P, Ciesielska M, Kucza M, et al. Prevention of Type 1 Diabetes: Past Experiences and Future OpportunitiesJ Clin Med. 2020;9(9):2805. doi:10.3390/jcm9092805

  18. Czupryniak L, Barkai L, Bolgarska S, et al. Self-monitoring of blood glucose in diabetes: from evidence to clinical reality in Central and Eastern Europe--recommendations from the international Central-Eastern European expert groupDiabetes Technol Ther. 2014;16(7):460-475. doi:10.1089/dia.2013.0302

  19. Centers for Disease Control and Prevention. What is type 1 diabetes?

Related Articles