Type 1 diabetes is a chronic, lifelong autoimmune condition in which the immune system mistakenly destroys the insulin producing β-cells of the pancreas. Typically, this means that the pancreas creates little or no insulin. Unlike type 2 diabetes (which is often associated with lifestyle factors), type 1 diabetes is not preventable, and does typically occur during childhood or adolescence (usually before age 15). However, type 1 diabetes can also occur in adults.

Insulin is a hormone needed to help regulate blood glucose levels and allows glucose (sugar) to move into cells where the glucose is used for energy. Where insulin is deficient, glucose becomes elevated in the blood system causing elevated blood sugar (hyperglycemia), which, if left untreated, can lead to a wide variety of serious health complications. For this reason, people with type 1 diabetes take daily synthetic insulin needed to sustain their life and health.

Type 1 diabetes was previously called “juvenile diabetes” or “insulin-dependent diabetes,” but “type 1 diabetes” is now the preferred name because it can occur in people at any age. However, type 1 diabetes always requires insulin therapy.

The precise causes of type 1 diabetes are still unknown, but experts believe it is a combination of environmental factors and genetic predisposition. Researchers have identified many important contributions to the development of this autoimmune condition: 

1. Autoimmune response: Type 1 diabetes is especially emphasized as an autoimmune disorder. Usually, the immune system is responsible for protecting the body from harmful things such as viruses and bacteria. In the case of type 1 diabetes, the immune system mistakenly kicks into gear and attacks the pancreas, destroying the beta cells that are responsible for the production of insulin. This destruction can occur slowly over time and is diagnosed when a certain amount of cells have been destroyed and the symptoms typically begin to appear. 
2. Genetics: Genetic factors play a significant role in the development of type 1 diabetes, particularly variations in the human leukocyte antigen (HLA) complex, which influences immune system function. While these genetic markers increase the likelihood of developing the disease, they do not guarantee its onset.
3. Environmental Triggers: Environmental factors are thought to be the initial step needed to instigate the autoimmune process in genetically predisposed individuals. Potential triggers include:
   • Viral infections (such as enteroviruses, rotavirus, or Epstein-Barr virus)
   • Introducing cow’s milk or some dietary proteins in the first year of life (research here is inconclusive) 
   • Environmental insults such as toxins, specific dietary constituents and other common factors. It is thought that these factors may instigate or accelerate an immune attack on the body’s pancreatic cells.
4. Family History: Although type 1 diabetes can develop without a family history of type 1 diabetes, if a parent or sibling has type 1 diabetes, the risk increases very slightly. Despite the very slight increased risk, most individuals diagnosed with type 1 diabetes do not have any close relatives with type 1 diabetes.

Notably, diet and lifestyle choices do not cause type 1 diabetes, while type 2 diabetes is associated with obesity, sedentary lifestyle patterns, and dietary intake; there is no cause-and-effect association that holds for the development of type 1 diabetes.

Lifestyle factors such as diet or activity do not cause type 1 diabetes, hence type 1 cannot be prevented. Type 1 diabetes is also not contagious; no one “catches” type 1 diabetes like a cold or flu.  Instead, type 1 diabetes occurs when the immune system mistakenly attacks and destroys beta cells (cells in the pancreas which make insulin). 

The autoimmune process can start long before symptoms of the disease develop; quite often, people have autoantibodies in their blood (autoantibodies are immune markers indicating attacks in the pancreas) for several months or years prior to being diagnosed. Some research studies can screen for autoantibodies particularly in children with family histories of type 1 diabetes to capture the disease before they ever progress to symptomatic diabetes.

Although no one knows exactly what makes the immune system attack the insulin-producing cells in the pancreas, researchers think that type 1 diabetes comes about through a complex interplay of several different factors:

• Family history: Having a parent, sibling, or other close relative with type 1 diabetes increases your risk somewhat. 
• Age: Type 1 diabetes usually occurs in children, adolescents or young adults, but it can happen at any age. 
• Genetic susceptibility: Certain genes (especially immune genes) may contribute to a person’s risk of developing type 1 diabetes.
• Environmental triggers: Some environmental contributors, such as viruses, might trigger the process of the immune system attacking its own insulin-producing cells, especially in genetically susceptible people. 
• Immune system deviation (failure): the immune system fails to maintain normal regulation, and the body instead attacks its own insulin-producing cells. 

Type 1 diabetes is the end stage result of a combination of genetic, immunologic and environmental triggers, many of which are out of a person’s control. and go away on its own, some people may develop chronic symptoms that repeat over months or even years.

The symptoms of type 1 diabetes can present very suddenly, with some developing over the course of days or a few weeks. Symptoms arise from the body’s inability to produce insulin and resulting in high blood glucose levels. It is important to recognize these signs early for both diagnosis and therapy, particularly in a child or adolescent. 

Here are the most common signs and symptoms of type 1 diabetes: 

1. Increased Thirst (Polydipsia): Exceedingly excessive sugar in the bloodstream will draw water from body tissues, leading a person to feel excessively thirsty. Constant thirst may be one of the first and clearest signs. 
2. Frequent Urination (Polyuria): Additional urine is produced by the kidneys when they try to dispose of the excess sugar in the bloodstream. The offer is an increased amount of frequent urination, usually most obvious at night. 
3. Increased Hunger (Polyphagia): Even if the person is eating normally, or more than usual, it is common for people with type 1 diabetes to feel hungry. This is because the body cannot use the glucose for energy as it should, so the brain says, “more food.”
4. Unintentional Weight Loss or Lack of Weight Gain: Even with increased hunger and food intake, people can lose weight because the body will use muscle and fat for energy when insulin is absent.
5. Fatigue: The body will not be able to utilize glucose for energy and will not receive energy from its primary source, thus causing constant lethargy and lack of energy.
6. Blurred Vision: Too much glucose in the system can cause the lens of the eye to swell, resulting in blurred or distorted vision. Blurred vision may improve once blood glucose is managed properly. 
7. Slow-healing wounds or recurrent skin, gum or urinary tract infections: High glucose levels can weaken the immune response and the body’s ability to heal, resulting in slow healing wounds or recurrent infections, especially skin and gum infections.
8. Fruity Breath: This odor is a classic sign of diabetic ketoacidosis (DKA), which is a serious complication of untreated type 1 diabetes.  This occurs when the body uses fat for energy and produces acidic ketones, which build up in the blood, causing the breath to have a fruity or acetone-smelling odor.
9. Nausea or vomiting: Often occurring with diabetic ketoacidosis, nausea and vomiting may become frequent and severe with accompanying dehydration. If nausea and vomiting occurs with stomach pain or difficulty breathing, you may need emergency medical help.
10. Bedwetting in Children (Enuresis): Children who previously slept dry may begin to wet the bed. In infants and toddlers, you may notice diaper changes with excessive wetness.
11. Mood Changes and Irritability: Rapid swings in blood sugar levels can impact emotional states. Such emotional disturbances can lead to mood changes, irritability, and even some signs of depression or anxiety in children and teens.
12. Recurring Vaginal Yeast Infections: Girls and women with undiagnosed type 1 diabetes may present with recurrent yeast infections. This is due to the sugar environment allowing yeast to grow.

Diagnosing type 1 diabetes involves looking at clinical signs, blood glucose levels, and markers that can differentiate it from other forms of diabetes. The goal of a timely diagnosis is to enable treatment as soon as possible and minimize the risk of life-threatening complications like diabetic ketoacidosis (DKA). 

Below are the most common tests and diagnostic procedures for type 1 diabetes: 

• Random Blood Sugar Test: The random blood sugar test measures blood glucose at any time of the day, regardless of when the person last ate. A random blood sugar level greater than 200 mg/dL (11.1 mmol/L) with classic signs of diabetes (such as urination, extreme thirst and unexplained weight loss) can confirm a diagnosis all on its own.
• Fasting Blood Sugar Test: The fasting blood sugar test measures blood glucose after someone fasts overnight (no eating or drinking with (water only) for at least 8 hours). 
  • Levels between 100–125 mg/dL (5.6–6.9 mmol/L) reflects prediabetes. 
  • A blood glucose of 126 mg/dL (7.0 mmol/L) or more could confirm a diagnosis of type 1 diabetes if measures on two different occasions.
• Glycated Hemoglobin (HbA1c) Test: Also known as the A1c test, this measures the average blood sugar levels over the previous 2–3 months.
  • A result of 6.5% or higher on two separate tests indicates diabetes.
  • This test is helpful in both diagnosis and long-term monitoring of glucose control.
• Oral Glucose Tolerance Test (OGTT): This test is mainly used to diagnose gestational or type 2 diabetes, though it may be occasionally utilized in cases of uncertainty. It measures blood sugar levels after fasting overnight, and then again two hours after ingesting a glucoseladen drink.
  • A 2-hour blood sugar level of 200 mg/dL (11.1 mmol/L) or higher indicates diabetes.
• C-Peptide Test: The C-peptide test measures the quantity of C-peptide, which is a byproduct of insulin production. Low or undetectable levels of C-peptide indicate that the pancreas is producing little or no insulin, which is found in type 1 diabetes.
• Autoantibodies Assessment: In some cases, with unclear presentations, autoimmune markers may help differentiate between type 1 and type 2 diabetes. The presence of marker autoantibodies lends strong support to using a diagnosis of type 1 diabetes.
  • Common antibodies for type 1 diabetes are:
    • GAD65 (Glutamic Acid Decarboxylase antibody)
    • IA-2 (Insulinoma-Associated Antigen 2 antibody)
    • ZnT8 (Zinc Transporter 8 antibody) 
    • IAA (Insulin Autoantibodies) – more common in young children
• Urinalysis: The use of urinalysis is particularly useful when the clinical presentation or symptoms are pointing towards the possibility of diabetic ketoacidosis (DKA).
  • When the presence of ketones in the urine is established, this indicates that the body is breaking down fat rather than using glucose, which highlights the body’s energy metabolic pathway.
  • If urine ketones are elevated, the likelihood of the body’s blood becoming acidic could be considered dangerous, if not life-threatening.
• Arterial Blood Gas (ABG) Test: This assessment measures blood pH and levels of oxygen and carbon dioxide. It is not only a useful tool in admission of suspected DKA patients, but it also is used to assess the severity of acidosis in a metabolic sense.
  • A low pH (acidic blood) is important in confirming metabolic acidosis.

There still isn’t a cure for type 1 diabetes. However, lots of individuals with this condition can lead long, healthy and active lives with proper management. The main focus of treatment is to keep blood sugar in a healthy range (usually 70-130mg/dL) to avoid or delay complications. Management of type 1 diabetes involves insulin treatment, blood glucose monitoring, a well-balanced healthy diet, regular physical activities, and ongoing education and support. 

1. Insulin Treatment: Individuals living with type 1 diabetes need to take insulin every day to survive, because their pancreas is not producing its own insulin. Since insulin cannot be taken in pill form (insulin would be broken down by enzymes in the stomach), they will receive it via: 
   • Insulin pens
   • Syringes
   • Insulin pumps
   • Automated insulin delivery systems linked with continuous glucose monitors (CGM).
   • Types of insulin include:
     • Rapid-acting insulin (e.g., lispro, aspart): It begins acting in minutes and is given at meal times.
     • Short-acting insulin (Regular insulin): It takes just a bit longer to act than rapid-acting insulin. 
     • Intermediate-acting insulin (e.g., NPH): It covers insulin requirement for part of a day or overnight. Long-acting insulin (e.g., glargine, detemir): It has a consistent level over 24 hours.
2. Blood Sugar Monitoring: You need to monitor blood sugar levels frequently to participate in effective diabetes management. Blood sugar levels should be checked at least four times a day, with more checks depending on the insulin therapy regimen and daily activities.
   • Ways to monitor blood sugar level include:
     • Fingerstick blood glucose meters.
     • Continuous glucose monitors (CGMs): allow real-time glucose monitoring and will notify the user when glucose is too high or low.
3. Healthy Diet: You need a well-balanced, low-fat, and high-fiber diet. Frequently, people with type 1 diabetes count carbohydrates to give the correct amount of insulin to match their carbohydrate intake. Carbohydrate counting helps maintain steady glucose levels during the day.
4. Physical Activity and Staying Healthy: Being active can improve insulin sensitivity, decrease blood glucose, and improve overall health. However, exercise can produce very unpredictable effects on blood sugar. It is important to check glucose before, during, and after physical activity. If needed, adjust insulin dosing or food intake.
5. Education and Support: Living with type 1 diabetes is a constant learning experience and can be isolated without support from others in the same or similar situation. Diabetes education programs can teach individuals and their families how to:
   • Inject insulin
   • Notice and treat low blood glucose (hypoglycemia)
   • Adjust their treatment in times of sickness, stress, or change in physical activity
   • Prevent complications in both the short- and long term
6. Personal Emergency Plan: People living with type 1 diabetes should always try to carry:
   • Samples of fast acting sugar (glucose tablets, juice)
   • Medical identification indicating diabetes
   • Glucagon emergency kit to treat hypoglycemia (if person is not able to eat / drink)
7. Medications: In addition to insulin, some medications may be prescribed to help protect against complications: 
   • Cholesterol-lowering medications: Statins are routinely prescribed as people with diabetes are at higher risk for heart disease. 
   • Blood pressure medications: An ACE inhibitor or ARB may be prescribed to help protect kidney function, particularly for those with elevated blood pressure (≥140/90 mm Hg).
   • Aspirin: Low-dose aspirin may be recommended for people at increased cardiovascular risk; bleeding risk will be assessed first.

Pregnancy has higher risks for someone with type 1 diabetes.

Reaching an A1c of less than 6.5% should be achieved before conception. 

Diabetes that is poorly controlled in the first 6-8 weeks of pregnancy significantly increases the risk of congenital defects in the fetus. 

Pregnancy involves close monitoring and adjustments to the diabetes management plan to help decrease risks and complications. 

Individuals who are older or have other serious health conditions and/or cognitive impairment may be unsafe with judicious glucose control. 

An A1c of less than 8% may be appropriate in these individuals to prevent hypoglycemia and other possible adverse events. 

All individuals with type 1 diabetes need consistent care to manage blood sugar levels and prevent complications. Long-term complications of poorly managed type 1 diabetes include: 

• Heart disease and stroke 
• Kidney damage (diabetic nephropathy) 
• Nerve damage (diabetic neuropathy) 
• Eye damage (diabetic retinopathy) 
• Foot problems and possible amputations 
• Increased risk of infections 
• Outcomes of poorly controlled diabetes include: 
• Acute complications such as: 
• Hypoglycemia (low blood sugar)
• Diabetic ketoacidosis (DKA)

Type 1 diabetes is serious, lifelong disease that requires an intensity of care and commitment. Although the cause of type 1 diabetes is still not understood and cannot be prevented, advancements in medical technology and treatment have positively impacted the quality of life and outcomes for people living with the disease.

With the right insulin therapy and glucose monitoring, healthy lifestyle choices and education, you and your family can manage type 1 diabetes. People living with type 1 diabetes can lead happy and productive lives with the ongoing potential of additional discoveries through future research, and the possibility of improved medical treatments and even a cure!

Understanding and awareness of the signs, risk factors and management of type 1 diabetes is important not only for the individual who has been diagnosed, but for families, health care professionals and the focused community at large. Early diagnosis and ongoing support can make a positive impact on healthy living with type 1 diabetes.

Receiving a diagnosis of type 1 diabetes is a life-changing experience, but it does not mean that one cannot go on to live a happy and healthy life. Initially, all the responsibilities may feel unfamiliar, overwhelming and impossible. However, with ongoing support and opportunities for knowledge about type 1 diabetes, along with enhancing your own body awareness, you may begin to feel more confident about managing diabetes.

• American Diabetes Association. (2024). Type 1 diabetes. https://diabetes.org/diabetes/type-1
• Centers for Disease Control and Prevention. (2023, October 20). What is type 1 diabetes? U.S. Department of Health & Human Services. 
• Mayo Clinic. (2024, January 10). Type 1 diabetes
• National Institute of Diabetes and Digestive and Kidney Diseases. (2023, August). Type 1 diabetes.